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
@@ -159,7 +159,6 @@
     #stat summary
     range =65
     @histogram = { data: Array.new(range,0), summary: {} }
-    @histogram[:data] = Array.new(range,0)
     user = Hash.new(0)
     @submissions.find_each do |sub|
       d = (DateTime.now.in_time_zone - sub.submitted_at) / 24 / 60 / 60
diff --git a/app/controllers/report_controller.rb b/app/controllers/report_controller.rb
--- a/app/controllers/report_controller.rb
+++ b/app/controllers/report_controller.rb
@@ -111,7 +111,6 @@
 
     range =65
     @histogram = { data: Array.new(range,0), summary: {} }
-    @histogram[:data] = Array.new(range,0)
     @summary = {count: 0, solve: 0, attempt: 0}
     user = Hash.new(0)
     Submission.where(problem_id: @problem.id).find_each do |sub|
diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -111,7 +111,25 @@
 
   def profile
     @user = User.find(params[:id])
-    @submission = Submission.where(user_id: params[:id]).all
+    @submission = Submission.includes(:problem).where(user_id: params[:id])
+
+    range = 120
+    @histogram = { data: Array.new(range,0), summary: {} }
+    @summary = {count: 0, solve: 0, attempt: 0}
+    problem = Hash.new(0)
+
+    @submission.find_each do |sub|
+      #histogram
+      d = (DateTime.now.in_time_zone - sub.submitted_at) / 24 / 60 / 60
+      @histogram[:data][d.to_i] += 1 if d < range
+
+      @summary[:count] += 1
+      problem[sub.problem] = [problem[sub.problem], (sub.points >= sub.problem.full_score) ? 1 : 0].max
+    end
+
+    @histogram[:summary][:max] = [@histogram[:data].max,1].max
+    @summary[:attempt] = problem.count
+    problem.each_value { |v| @summary[:solve] += 1 if v == 1 }
   end
 
   protected
diff --git a/app/views/application/_bar_graph.html.haml b/app/views/application/_bar_graph.html.haml
--- a/app/views/application/_bar_graph.html.haml
+++ b/app/views/application/_bar_graph.html.haml
@@ -18,7 +18,7 @@
     font-size:5px;
   }
 
-%div{style: "position: relative; width: #{graph_width}px; height: 150px; background-color:#fff;" }
+%div{style: "position: relative; width: #{graph_width}px; height: 125px; background-color:#fff;" }
   //draw background
   - histogram[:data].each_index do |i|
     - height = histogram[:data][i] * graph_height / histogram[:summary][:max]
diff --git a/app/views/report/_task_hof.html.haml b/app/views/report/_task_hof.html.haml
--- a/app/views/report/_task_hof.html.haml
+++ b/app/views/report/_task_hof.html.haml
@@ -1,8 +1,39 @@
+- content_for :header do
+  = javascript_include_tag 'local_jquery'
+
+:javascript
+  $(document).ready( function() {
+    $("#mem_remark").hover( function() {
+      $("#mem_remark_box").show();
+    }, function() {
+      $("#mem_remark_box").hide();
+    });
+  });
+  alert("hahaha");
 :css
   .hof_user { color: orangered; font-style: italic; }
   .hof_language { color: green; font-style: italic; }
   .hof_value { color: deeppink;font-style: italic; }
   .info_param { font-weight: bold;text-align: right; }
+  .tooltip {
+    font-family: Verdana,sans-serif;
+    font-weight: normal;
+    text-align: left;
+    font-size: 1.0em;
+    color: black;
+    line-height: 1.1;
+    display: none;
+    min-width: 20em;
+    position: absolute;
+    left: 25px;
+    bottom: 5px;
+    border: 1px solid;
+    padding: 5px;
+    background-color: #FFF;
+    word-wrap: break-word;
+    z-index: 9999;
+    overflow: auto;
+  }
 
 %h1 (#{Problem.find(params[:id]).name}) #{Problem.find(params[:id]).full_name}
 
@@ -30,7 +61,13 @@
           = link_to("#" + @best[:runtime][:sub_id].to_s, controller: 'graders', action: 'submission', id:@best[:runtime][:sub_id])
 
       %tr{class: cycle('info-even','info-odd')}
-        %td.info_param Best Memory Usage
+        %td.info_param
+          Best Memory Usage
+          %sup{ id: "mem_remark", style: "position:relative; color: blue;"} 
+            [?]
+            %span.tooltip#mem_remark_box
+              This counts only for submission with 100% score.
+              Right now, java is excluded from memory usage competition. (Because it always uses 2GB memory...)
         %td
           by #{link_to @best[:memory][:user], controller:'users', action:'profile', id:@best[:memory][:user_id]} 
           using <span class="hof_language">#{@best[:memory][:lang]}</span> 
@@ -56,11 +93,6 @@
           at submission
           = link_to("#" + @best[:first][:sub_id].to_s, controller: 'graders' , action: 'submission', id: @best[:first][:sub_id])
 
-
-%p
-  This counts only for submission with 100% score <br/>
-  Right now, java is excluded from memory usage competition. (Because it always uses 2GB memory...)
-
 - if @best
   %h2 By language
 
diff --git a/app/views/users/profile.html.haml b/app/views/users/profile.html.haml
--- a/app/views/users/profile.html.haml
+++ b/app/views/users/profile.html.haml
@@ -1,9 +1,9 @@
 - content_for :header do
   = javascript_include_tag 'local_jquery'
 
-%script{:type=>"text/javascript"}
+:javascript
   $(function () {
-  $('#submission_table').tablesorter({widgets: ['zebra']});
+    $('#submission_table').tablesorter({widgets: ['zebra']});
   });
 
 :css
@@ -11,16 +11,30 @@
     font-family: Droid Sans Mono,Consolas, monospace, mono, Courier New, Courier;
   }
 
-%h1= @user.full_name + ' Profile'
+%h1= @user.full_name
 
-%h2 Basic info
 <b>Login:</b> #{@user.login} <br/>
 <b>Full name:</b> #{@user.full_name} <br />
 
 
 %h2 Problem Stat
+%table.info
+  %thead
+    %tr.info-head
+      %th Stat
+      %th Value
+  %tbody
+    %tr{class: cycle('info-even','info-odd')}
+      %td.info_param Submissions
+      %td= @summary[:count]
+    %tr{class: cycle('info-even','info-odd')}
+      %td.info_param Solved/Attempted Problem
+      %td #{@summary[:solve]}/#{@summary[:attempt]} (#{(@summary[:solve]*100.0/@summary[:attempt]).round(1)}%)
 
-%h2 Submissions
+%h2 Submission History
+
+=render partial: 'application/bar_graph', locals: {histogram: @histogram, param: {bar_width: 7}}
+
 
 %table.tablesorter-cafe#submission_table
   %thead