diff --git a/app/controllers/groups_controller.rb b/app/controllers/groups_controller.rb
new file mode 100644
--- /dev/null
+++ b/app/controllers/groups_controller.rb
@@ -0,0 +1,86 @@
+class GroupsController < ApplicationController
+  before_action :set_group, only: [:show, :edit, :update, :destroy,
+                                   :add_user, :remove_user,
+                                   :add_problem, :remove_problem,
+                                  ]
+  before_action :authenticate, :admin_authorization
+
+  # GET /groups
+  def index
+    @groups = Group.all
+  end
+
+  # GET /groups/1
+  def show
+  end
+
+  # GET /groups/new
+  def new
+    @group = Group.new
+  end
+
+  # GET /groups/1/edit
+  def edit
+  end
+
+  # POST /groups
+  def create
+    @group = Group.new(group_params)
+
+    if @group.save
+      redirect_to @group, notice: 'Group was successfully created.'
+    else
+      render :new
+    end
+  end
+
+  # PATCH/PUT /groups/1
+  def update
+    if @group.update(group_params)
+      redirect_to @group, notice: 'Group was successfully updated.'
+    else
+      render :edit
+    end
+  end
+
+  # DELETE /groups/1
+  def destroy
+    @group.destroy
+    redirect_to groups_url, notice: 'Group was successfully destroyed.'
+  end
+
+  def remove_user
+    user = User.find(params[:user_id])
+    @group.users.delete(user)
+    redirect_to group_path(@group), notice: "User #{user.login} was removed from the group #{@group.name}"
+  end
+
+  def add_user
+    user = User.find(params[:user_id])
+    @group.users << user
+    redirect_to group_path(@group), notice: "User #{user.login} was add to the group #{@group.name}"
+  end
+
+  def remove_problem
+    problem = Problem.find(params[:problem_id])
+    @group.problems.delete(problem)
+    redirect_to group_path(@group), notice: "Problem #{problem.name} was removed from the group #{@group.name}"
+  end
+
+  def add_problem
+    problem = Problem.find(params[:problem_id])
+    @group.problems << problem
+    redirect_to group_path(@group), notice: "Problem #{problem.name} was add to the group #{@group.name}"
+  end
+
+  private
+    # Use callbacks to share common setup or constraints between actions.
+    def set_group
+      @group = Group.find(params[:id])
+    end
+
+    # Only allow a trusted parameter "white list" through.
+    def group_params
+      params.require(:group).permit(:name, :description)
+    end
+end
diff --git a/app/controllers/problems_controller.rb b/app/controllers/problems_controller.rb
--- a/app/controllers/problems_controller.rb
+++ b/app/controllers/problems_controller.rb
@@ -195,6 +195,11 @@
       set_available(true)
     elsif params.has_key? 'disable_problem'
       set_available(false)
+    elsif params.has_key? 'add_group'
+      group = Group.find(params[:group_id])
+      get_problems_from_params.each do |p|
+        group.problems << p
+      end
     end
     redirect_to :action => 'manage'
   end
diff --git a/app/controllers/user_admin_controller.rb b/app/controllers/user_admin_controller.rb
--- a/app/controllers/user_admin_controller.rb
+++ b/app/controllers/user_admin_controller.rb
@@ -440,10 +440,9 @@
           u.save
         end
       end
-      if @action[:add_group]
-        @uses.each do |u|
-
-        end
+      if @action[:add_group] and @action[:group_name]
+        @group = Group.find(@action[:group_name])
+        @users.each { |user|  @group.users << user }
       end
     end
   end
diff --git a/app/helpers/groups_helper.rb b/app/helpers/groups_helper.rb
new file mode 100644
--- /dev/null
+++ b/app/helpers/groups_helper.rb
@@ -0,0 +1,2 @@
+module GroupsHelper
+end
diff --git a/app/models/grader_configuration.rb b/app/models/grader_configuration.rb
--- a/app/models/grader_configuration.rb
+++ b/app/models/grader_configuration.rb
@@ -12,6 +12,7 @@
   MULTIPLE_IP_LOGIN_KEY = 'right.multiple_ip_login'
   VIEW_TESTCASE = 'right.view_testcase'
   SINGLE_USER_KEY = 'system.single_user_mode'
+  SYSTEM_USE_PROBLEM_GROUP = 'system.use_problem_group'
 
   cattr_accessor :config_cache
   cattr_accessor :task_grading_info_cache
@@ -119,6 +120,10 @@
   def self.analysis_mode?
     return get(SYSTEM_MODE_CONF_KEY) == 'analysis'
   end
+
+  def self.use_problem_group?
+    return get(SYSTEM_USE_PROBLEM_GROUP)
+  end
   
   def self.contest_time_limit
     contest_time_str = GraderConfiguration[CONTEST_TIME_LIMIT_KEY]
diff --git a/app/models/group.rb b/app/models/group.rb
new file mode 100644
--- /dev/null
+++ b/app/models/group.rb
@@ -0,0 +1,5 @@
+class Group < ActiveRecord::Base
+  has_and_belongs_to_many :problems
+  has_and_belongs_to_many :users
+end
+
diff --git a/app/models/problem.rb b/app/models/problem.rb
--- a/app/models/problem.rb
+++ b/app/models/problem.rb
@@ -2,6 +2,7 @@
 
   belongs_to :description
   has_and_belongs_to_many :contests, :uniq => true
+  has_and_belongs_to_many :groups
   has_many :test_pairs, :dependent => :delete_all
   has_many :testcases, :dependent => :destroy
 
diff --git a/app/models/user.rb b/app/models/user.rb
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -7,6 +7,7 @@
 class User < ActiveRecord::Base
 
   has_and_belongs_to_many :roles
+  has_and_belongs_to_many :groups
 
   has_many :test_requests, -> {order(submitted_at: DESC)}
 
@@ -290,7 +291,11 @@
 
   def available_problems
     if not GraderConfiguration.multicontests?
-      return Problem.available_problems
+      if GraderConfiguration.use_problem_group?
+        return available_problems_in_group
+      else
+        return Problem.available_problems
+      end
     else
       contest_problems = []
       pin = {}
@@ -307,6 +312,14 @@
     end
   end
 
+  def available_problems_in_group
+    problem = []
+    self.groups.each do |group|
+      group.problems.where(available: true).each { |p| problem << p }
+    end
+    return problem.uniq
+  end
+
   def can_view_problem?(problem)
     if not GraderConfiguration.multicontests?
       return problem.available
diff --git a/app/views/groups/_form.html.haml b/app/views/groups/_form.html.haml
new file mode 100644
--- /dev/null
+++ b/app/views/groups/_form.html.haml
@@ -0,0 +1,16 @@
+= form_for @group do |f|
+  - if @group.errors.any?
+    #error_explanation
+      %h2= "#{pluralize(@group.errors.count, "error")} prohibited this group from being saved:"
+      %ul
+        - @group.errors.full_messages.each do |msg|
+          %li= msg
+
+  .form-group.field
+    = f.label :name
+    = f.text_field :name, class: 'form-control'
+  .form-group.field
+    = f.label :description
+    = f.text_field :description, class: 'form-control'
+  .form-group.actions
+    = f.submit 'Save', class: 'btn btn-primary'
diff --git a/app/views/groups/edit.html.haml b/app/views/groups/edit.html.haml
new file mode 100644
--- /dev/null
+++ b/app/views/groups/edit.html.haml
@@ -0,0 +1,7 @@
+%h1 Editing group
+
+= render 'form'
+
+= link_to 'Show', @group
+\|
+= link_to 'Back', groups_path
diff --git a/app/views/groups/index.html.haml b/app/views/groups/index.html.haml
new file mode 100644
--- /dev/null
+++ b/app/views/groups/index.html.haml
@@ -0,0 +1,24 @@
+%h1 Groups
+
+%p
+  = link_to 'New Group', new_group_path, class: 'btn btn-primary'
+%table.table.table-hover
+  %thead
+    %tr
+      %th Name
+      %th Description
+      %th
+      %th
+      %th
+
+  %tbody
+    - @groups.each do |group|
+      %tr
+        %td= group.name
+        %td= group.description
+        %td= link_to 'Show', group, class: 'btn btn-default'
+        %td= link_to 'Edit', edit_group_path(group), class: 'btn btn-default'
+        %td= link_to 'Destroy', group, :method => :delete, :data => { :confirm => 'Are you sure?' }, class: 'btn btn-danger'
+
+%br
+
diff --git a/app/views/groups/new.html.haml b/app/views/groups/new.html.haml
new file mode 100644
--- /dev/null
+++ b/app/views/groups/new.html.haml
@@ -0,0 +1,5 @@
+%h1 New group
+
+= render 'form'
+
+= link_to 'Back', groups_path
diff --git a/app/views/groups/show.html.haml b/app/views/groups/show.html.haml
new file mode 100644
--- /dev/null
+++ b/app/views/groups/show.html.haml
@@ -0,0 +1,67 @@
+%p#notice= notice
+
+%p
+  %b Name:
+  = @group.name
+%p
+  %b Description:
+  = @group.description
+
+%br
+= link_to 'Edit', edit_group_path(@group)
+\|
+= link_to 'Back', groups_path
+
+.row
+  .col-md-6
+    %h1 Users in this group
+
+    =form_tag add_user_group_path(@group), class: 'form-inline' do
+      .form-group
+        =label_tag :user_id, "User"
+        =select_tag :user_id, options_from_collection_for_select(User.all,'id','full_name'), class: 'select2'
+      =submit_tag "Add",class: 'btn btn-primary'
+
+
+    %table.table.table-hover
+      %thead
+        %tr
+          %th Login
+          %th Full name
+          %th Remark
+          %th
+
+      %tbody
+        - @group.users.each do |user|
+          %tr
+            %td= user.login
+            %td= user.full_name
+            %td= user.remark
+            %td= link_to 'Remove', remove_user_group_path(@group,user), :method => :delete, :data => { :confirm => "Remove #{user.full_name}?" }, class: 'btn btn-danger'
+  .col-md-6
+    %h1 Problems in this group
+
+    =form_tag add_problem_group_path(@group), class: 'form-inline' do
+      .form-group
+        =label_tag :problem_id, "Problem"
+        =select_tag :problem_id, options_from_collection_for_select(Problem.all,'id','full_name'), class: 'select2'
+      =submit_tag "Add",class: 'btn btn-primary'
+
+
+    %table.table.table-hover
+      %thead
+        %tr
+          %th name
+          %th Full name
+          %th Full score
+          %th
+
+      %tbody
+        - @group.problems.each do |problem|
+          %tr
+            %td= problem.name
+            %td= problem.full_name
+            %td= problem.full_score
+            %td= link_to 'Remove', remove_problem_group_path(@group,problem), :method => :delete, :data => { :confirm => "Remove #{problem.full_name}?" }, class: 'btn btn-danger'
+
+
diff --git a/app/views/problems/manage.html.haml b/app/views/problems/manage.html.haml
--- a/app/views/problems/manage.html.haml
+++ b/app/views/problems/manage.html.haml
@@ -39,7 +39,7 @@
 %p= link_to '[Back to problem list]', :action => 'list'
 
 = form_tag :action=>'do_manage' do
-  .submitbox
+  .submitbox.panel
     What do you want to do to the selected problem?
     %br/
     (You can shift-click to select a range of problems)
@@ -59,8 +59,13 @@
           Add to 
           = select("contest","id",Contest.all.collect {|c| [c.title, c.id]})
           = submit_tag 'Add', :name => 'add_to_contest'
+      %li
+        Add problems to group
+        = select_tag "group_id", options_from_collection_for_select( Group.all, 'id','name',params[:group_name]), id: 'group_name',class: 'select2'
+        = submit_tag 'Add', name: 'add_group'
+          
 
-  %table
+  %table.table.table-hover
     %tr{style: "text-align: left;"}
       %th= check_box_tag 'select_all'
       %th Name
diff --git a/app/views/user_admin/bulk_manage.html.haml b/app/views/user_admin/bulk_manage.html.haml
--- a/app/views/user_admin/bulk_manage.html.haml
+++ b/app/views/user_admin/bulk_manage.html.haml
@@ -53,7 +53,7 @@
               Add users to group
           %label.col-md-3.control-label.text-right Group name
           .col-md-5
-            = text_field_tag "group_name", params[:group_name], id: 'group_name',class: 'form-control select2'
+            = select_tag "group_name", options_from_collection_for_select( Group.all, 'id','name',params[:group_name]), id: 'group_name',class: 'form-control select2'
 
 
 .row
diff --git a/config/routes.rb b/config/routes.rb
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -29,7 +29,15 @@
       get 'import'
       get 'manage'
     end
+  end
 
+  resources :groups do
+    member do
+      post 'add_user', to: 'groups#add_user', as: 'add_user'
+      delete 'remove_user/:user_id', to: 'groups#remove_user', as: 'remove_user'
+      post 'add_problem', to: 'groups#add_problem', as: 'add_problem'
+      delete 'remove_problem/:problem_id', to: 'groups#remove_problem', as: 'remove_problem'
+    end
   end
 
   resources :testcases, only: [] do
diff --git a/db/migrate/20170911091143_create_groups.rb b/db/migrate/20170911091143_create_groups.rb
new file mode 100644
--- /dev/null
+++ b/db/migrate/20170911091143_create_groups.rb
@@ -0,0 +1,30 @@
+class CreateGroups < ActiveRecord::Migration
+
+  def change
+    create_table :groups do |t|
+      t.string :name
+      t.string :description
+    end
+
+    create_join_table :groups, :users do |t|
+      # t.index [:group_id, :user_id]
+      t.index [:user_id, :group_id]
+    end
+
+    create_join_table :problems, :groups do |t|
+      # t.index [:problem_id, :group_id]
+      t.index [:group_id, :problem_id]
+    end
+
+    reversible do |change|
+      change.up do
+        GraderConfiguration.where(key: 'system.use_problem_group').first_or_create(value_type: 'boolean', value: 'false',
+                                                                                   description: 'If true, available problem to the user will be only ones associated with the group of the user');
+      end
+
+      change.down do
+        GraderConfiguration.where(key: 'system.use_problem_group').destroy_all
+      end
+    end
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20170427070345) do
+ActiveRecord::Schema.define(version: 20170911091143) do
 
   create_table "announcements", force: :cascade do |t|
     t.string   "author",       limit: 255
@@ -79,6 +79,25 @@
 
   add_index "grader_processes", ["host", "pid"], name: "index_grader_processes_on_ip_and_pid", using: :btree
 
+  create_table "groups", force: :cascade do |t|
+    t.string "name",        limit: 255
+    t.string "description", limit: 255
+  end
+
+  create_table "groups_problems", id: false, force: :cascade do |t|
+    t.integer "problem_id", limit: 4, null: false
+    t.integer "group_id",   limit: 4, null: false
+  end
+
+  add_index "groups_problems", ["group_id", "problem_id"], name: "index_groups_problems_on_group_id_and_problem_id", using: :btree
+
+  create_table "groups_users", id: false, force: :cascade do |t|
+    t.integer "group_id", limit: 4, null: false
+    t.integer "user_id",  limit: 4, null: false
+  end
+
+  add_index "groups_users", ["user_id", "group_id"], name: "index_groups_users_on_user_id_and_group_id", using: :btree
+
   create_table "heart_beats", force: :cascade do |t|
     t.integer  "user_id",    limit: 4
     t.string   "ip_address", limit: 255
diff --git a/db/seeds.rb b/db/seeds.rb
--- a/db/seeds.rb
+++ b/db/seeds.rb
@@ -163,7 +163,16 @@
      :value_type => 'string',
      :default_value => 'none',
      :description => "New user will be assigned to this contest automatically, if it exists.  Set to 'none' if there is no default contest."
-   }
+   },
+
+   {
+     :key => 'system.use_problem_group',
+     :value_type => 'boolean',
+     :default_value => 'false',
+     :description => "If true, available problem to the user will be only ones associated with the group of the user."
+   },
+
+
 
   ]
 
diff --git a/test/controllers/groups_controller_test.rb b/test/controllers/groups_controller_test.rb
new file mode 100644
--- /dev/null
+++ b/test/controllers/groups_controller_test.rb
@@ -0,0 +1,49 @@
+require 'test_helper'
+
+class GroupsControllerTest < ActionController::TestCase
+  setup do
+    @group = groups(:one)
+  end
+
+  test "should get index" do
+    get :index
+    assert_response :success
+    assert_not_nil assigns(:groups)
+  end
+
+  test "should get new" do
+    get :new
+    assert_response :success
+  end
+
+  test "should create group" do
+    assert_difference('Group.count') do
+      post :create, group: { description: @group.description, name: @group.name }
+    end
+
+    assert_redirected_to group_path(assigns(:group))
+  end
+
+  test "should show group" do
+    get :show, id: @group
+    assert_response :success
+  end
+
+  test "should get edit" do
+    get :edit, id: @group
+    assert_response :success
+  end
+
+  test "should update group" do
+    patch :update, id: @group, group: { description: @group.description, name: @group.name }
+    assert_redirected_to group_path(assigns(:group))
+  end
+
+  test "should destroy group" do
+    assert_difference('Group.count', -1) do
+      delete :destroy, id: @group
+    end
+
+    assert_redirected_to groups_path
+  end
+end