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
@@ -407,6 +407,39 @@
     redirect_to :action => 'mass_mailing'
   end
 
+  #bulk manage
+  def bulk_manage
+
+    begin 
+      @users = User.where('login REGEXP ?',params[:regex]) if params[:regex]
+      @users.count if @users #i don't know why I have to call count, but if I won't exception is not raised
+    rescue Exception
+      flash[:error] = 'Regular Expression is malformed'
+      @users = nil
+    end
+
+    if params[:commit]
+      @action = {}
+      @action[:set_enable] = params[:enabled]
+      @action[:enabled] = params[:enable] == "1"
+      @action[:gen_password] = params[:gen_password]
+    end
+
+    if params[:commit] == "Perform"
+      if @action[:set_enable]
+        @users.update_all(enabled: @action[:enabled])
+      end
+      if @action[:gen_password]
+        @users.each do |u|
+          password = random_password
+          u.password = password
+          u.password_confirmation = password
+          u.save
+        end
+      end
+    end
+  end
+
   protected
 
   def random_password(length=5)
diff --git a/app/models/problem.rb b/app/models/problem.rb
--- a/app/models/problem.rb
+++ b/app/models/problem.rb
@@ -61,7 +61,9 @@
     result = Hash.new
     #total number of submission
     result[:total_sub] = Submission.where(problem_id: self.id).count
-    result[:attempted_user] = Submission.where(problem_id: self.id).group_by(:user_id)
+    result[:attempted_user] = Submission.where(problem_id: self.id).group(:user_id)
+    result[:pass] = Submission.where(problem_id: self.id).where("points >= ?",self.full_score).count
+    return result
   end
 
   def long_name
diff --git a/app/views/main/_problem.html.haml b/app/views/main/_problem.html.haml
--- a/app/views/main/_problem.html.haml
+++ b/app/views/main/_problem.html.haml
@@ -1,8 +1,12 @@
 %tr
   %td
-    = "#{problem.name}"
+    - if @current_user and @current_user.admin?
+      = link_to problem.name, stat_problem_path(problem)
+    - else
+      = "#{problem.name}"
   %td
     = "#{problem.full_name}"
+
     %br
     = link_to_description_if_any "[#{t 'main.problem_desc'}] <span class='glyphicon glyphicon-file'></span>".html_safe, problem
   %td
diff --git a/app/views/user_admin/bulk_manage.html.haml b/app/views/user_admin/bulk_manage.html.haml
new file mode 100644
--- /dev/null
+++ b/app/views/user_admin/bulk_manage.html.haml
@@ -0,0 +1,77 @@
+%h1 Bulk Manage User
+
+= form_tag bulk_manage_user_admin_path
+.row
+  .col-md-6
+    .panel.panel-primary
+      .panel-title.panel-heading
+        Filter User
+      .panel-body
+        Filtering users whose login match the following MySQL regex
+        .form-group
+          = label_tag "regex", 'Regex Pattern'
+          = text_field_tag "regex", params[:regex], class: 'form-control'
+        %p
+          Example
+        %ul
+          %li
+            %code root
+            matches every user whose login contains "root"
+          %li
+            %code ^56
+            matches every user whose login starts with "56"
+          %li
+            %code 21$
+            matches every user whose login ends with "21"
+  .col-md-6
+    .panel.panel-primary
+      .panel-title.panel-heading
+        Action
+      .panel-body
+        .row.form-group
+          .col-md-6
+            %label.checkbox-inline
+              = check_box_tag "enabled", true, params[:enabled]
+              Change "Enabled" to
+          .col-md-3
+            %label.radio-inline
+              = radio_button_tag "enable", 1, params[:enable] == '1', id: 'enable-yes'
+              Yes
+          .col-md-3
+            %label.radio-inline
+              = radio_button_tag "enable", 0, params[:enable] == '0', id: 'enable-no'
+              No
+        .row.form-group
+          .col-md-6
+            %label.checkbox-inline
+              = check_box_tag "gen_password", true, params[:gen_password]
+              Generate new random password
+
+.row
+  .col-md-12
+    = submit_tag "Preview Result", class: 'btn btn-default'
+- if @users
+  .row
+    .col-md-4
+      - if @action
+        %h2 Confirmation
+        - if @action[:set_enable]
+          .alert.alert-info The following users will be set #{(@action[:enabled] ? 'enable' : 'disable')}.
+        - if @action[:gen_password]
+          .alert.alert-info The password of the following users will be randomly generated.
+  .row
+    .col-md-4
+      = submit_tag "Perform", class: 'btn btn-primary'
+  .row
+    .col-md-12
+      The pattern matches #{@users.count} following users.
+      %br
+      - @users.each do |user|
+        = user.login
+        = ' '
+        = user.full_name
+        = ' '
+        = "(#{user.remark})" if user.remark
+        %br
+
+
diff --git a/app/views/user_admin/index.html.haml b/app/views/user_admin/index.html.haml
--- a/app/views/user_admin/index.html.haml
+++ b/app/views/user_admin/index.html.haml
@@ -42,6 +42,7 @@
   = link_to '+ New user', { :action => 'new' }, { class: 'btn btn-success '}
   = link_to '+ New list of users', { :action => 'new_list' }, { class: 'btn btn-success '}
   = link_to 'View administrators',{ :action => 'admin'}, { class: 'btn btn-default '}
+  = link_to 'Bulk Manage', bulk_manage_user_admin_path , { class: 'btn btn-default '}
   = link_to 'Random passwords',{ :action => 'random_all_passwords'}, { class: 'btn btn-default '}
   = link_to 'View active users',{ :action => 'active'}, { class: 'btn btn-default '}
   = link_to 'Mass mailing',{ :action => 'mass_mailing'}, { class: 'btn btn-default '}
diff --git a/app/views/user_admin/new_list.html.erb b/app/views/user_admin/new_list.html.erb
--- a/app/views/user_admin/new_list.html.erb
+++ b/app/views/user_admin/new_list.html.erb
@@ -1,8 +1,9 @@
 <h1>Adding list of users</h1>
 
 <%= form_tag :action => 'create_from_list' do %>
-<%= submit_tag 'create users' %><br/>
-List of user information in this format: <tt>user_id,name(,passwd(,alias))</tt><br/>
-Note that <tt>passwd</tt> and <tt>alias</tt> is optional.<br/>
+  <%= submit_tag 'create users',class: 'btn btn-success'%><br/>
+List of user information in this format: <tt>user_id,name(,passwd(,alias(,remark)))</tt><br/>
+Note that <tt>passwd, alias</tt> and <tt> remark </tt>is optional.<br />
+When <tt>passwd</tt> or <tt>alias</tt> is empty, the original value will be used instead.<br/>
 <%= text_area_tag 'user_list', nil, :rows => 50, :cols => 80 %>
 <% end %>
diff --git a/config/routes.rb b/config/routes.rb
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -63,14 +63,15 @@
     end
   end
 
-  get 'tasks/view/:file.:ext' => 'tasks#view'
-  get 'tasks/download/:id/:file.:ext' => 'tasks#download'
-  get 'heartbeat/:id/edit' => 'heartbeat#edit'
+
 
   #main
   get "main/list"
   get 'main/submission(/:id)', to: 'main#submission', as: 'main_submission'
 
+  #user admin
+  get 'user_admin/bulk_manage', to: 'user_admin#bulk_manage', as: 'bulk_manage_user_admin'
+
   #report
   get 'report/current_score', to: 'report#current_score', as: 'report_current_score'
   get 'report/problem_hof(/:id)', to: 'report#problem_hof', as: 'report_problem_hof'
@@ -78,6 +79,12 @@
   get 'report/max_score', to: 'report#max_score', as: 'report_max_score'
   post 'report/show_max_score', to: 'report#show_max_score', as: 'report_show_max_score'
 
+
+  #
+  get 'tasks/view/:file.:ext' => 'tasks#view'
+  get 'tasks/download/:id/:file.:ext' => 'tasks#download'
+  get 'heartbeat/:id/edit' => 'heartbeat#edit'
+
   #grader
   get 'graders/list', to: 'graders#list', as: 'grader_list'