diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index 1c2db7f79..063d32b84 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -255,112 +255,63 @@ class UsersController < ApplicationController
 
   #end
   def index
-   
-    @project_type = params[:project_type]
-    role = params[:role]
-    
+    @status = params[:status] || 1
     sort_init 'login', 'asc'
     sort_update %w(login firstname lastname mail admin created_on last_login_on)
 
+    # Deprecation
+    @project_type = params[:project_type]
+
     case params[:format]
     when 'xml', 'json'
       @offset, @limit = api_offset_and_limit({:limit => 15})
     else
-    @limit = 15#per_page_option
+      @limit = 15
     end
 
-    @status = params[:status] || 1
-    has = {
-      "show_changesets" => true
-    }
-    # @count = Redmine::Activity::Fetcher.new(User.current, :author => @user).scope_select {|t| !has["show_#{t}"].nil?}.events(nil, nil).count
-    
+    # retrieve all users
     scope = UserStatus.visible
-    case role
+
+    # if role has something, change scope.
+    case params[:role]
     when 'teacher'
       scope = UserStatus.teacher
     when 'student'
       scope = UserStatus.student
     else
-      
     end
     
+    # unknow
     scope = scope.in_group(params[:group_id]) if params[:group_id].present?
-    # scope.each do |user|
-      # UserStatus.create(:changesets_count => user.changesets.count, :watchers_count => user.watcher_users.count, :user_id => user.id)
-    # end
+
+    # pagination
     @user_count = scope.count
     @user_pages = Paginator.new @user_count, @limit, params['page']
-    #@offset ||= @user_pages.offset
-    #@users =  scope.order(sort_clause).limit(@limit).offset(@offset).all
-    @user_base_tag = params[:id] ? 'base_users':'base'
-      if params[:user_sort_type].present?
-      case params[:user_sort_type]
-      when '0'
-        @offset ||= @user_pages.reverse_offset
-        unless @offset == 0
-          @users_statuses = scope.offset(@offset).limit(@limit).all.reverse
-        else
-          limit = @user_count % @limit
-          if limit == 0
-            limit = @limit
-          end
-          @users_statuses = scope.offset(@offset).limit(limit).all.reverse
-        end
-        @s_type = 0
-        # @projects = @projects.sort {|x,y| y.created_on <=> x.created_on }
-        # @projects = @projects[@offset, @limit]
-      when '1'
-        @offset ||= @user_pages.reverse_offset
-        unless @offset == 0
-          @users_statuses = scope.reorder('grade').offset(@offset).limit(@limit).all.reverse
-        else
-          limit = @user_count % @limit
-          if limit == 0
-            limit = @limit
-          end
-          @users_statuses = scope.reorder('grade').offset(@offset).limit(limit).all.reverse
-        end
-        @s_type = 1
-        #sort {|x,y| y.user_status.changesets_count <=> x.user_status.changesets_count}
-        #@users = @users[@offset, @limit]
-      when '2'
-        @offset ||= @user_pages.reverse_offset
-        unless @offset == 0
-          @users_statuses = scope.reorder('watchers_count').offset(@offset).limit(@limit).all.reverse
-        else
-          limit = @user_count % @limit
-          if limit == 0
-            limit = @limit
-          end
-          @users_statuses = scope.reorder('watchers_count').offset(@offset).limit(limit).all.reverse
-        end
-        @s_type = 2
-        #@users = @users[@offset, @limit]
-      end
 
+    # users classify
+    case params[:user_sort_type]
+    when '0'
+      @s_type = 0
+      @us_ordered =  scope.
+                      joins("LEFT JOIN users ON user_statuses.user_id = users.id").
+                      reorder('users.created_on DESC')
+    when '1'
+      @s_type = 1
+      @us_ordered =  scope.reorder('user_statuses.grade DESC')
+    when '2'
+      @s_type = 2
+      @us_ordered =  scope.reorder('user_statuses.watchers_count DESC')
     else
-      @offset ||= @user_pages.reverse_offset
-        unless @offset == 0
-          @users_statuses = scope.reorder('grade').offset(@offset).limit(@limit).all.reverse
-        else
-          limit = @user_count % @limit
-          if limit == 0
-            limit = @limit
-          end
-          @users_statuses = scope.reorder('grade').offset(@offset).limit(limit).all.reverse
-        end
-        @s_type = 1
-      # @projects = @projects.sort {|x,y| y.created_on <=> x.created_on }
-      # @projects = @projects[@offset, @limit]
-    end
-    
-    @users = []
-    @users_statuses.each do |obj|
-      @users << User.find_by_id("#{obj.user_id}")
+      @s_type = 1
+      @us_ordered =  scope.reorder('user_statuses.grade DESC')
     end
-    
+
+    # limit and offset
+    @users_statuses = @us_ordered.offset(@user_pages.offset).limit(@user_pages.per_page)
+    # get users ActiveRecord
+    @users = @users_statuses.map(&:user)
    
+    @user_base_tag = params[:id] ? 'base_users':'base'
     respond_to do |format|
       format.html {
         @groups = Group.all.sort
diff --git a/app/models/user_status.rb b/app/models/user_status.rb
index f6dd0c8b6..3b4d38373 100644
--- a/app/models/user_status.rb
+++ b/app/models/user_status.rb
@@ -1,6 +1,6 @@
 class UserStatus < ActiveRecord::Base
   attr_accessible :changesets_count, :user_id, :watchers_count
-  belongs_to :users
+  belongs_to :user
   belongs_to :watchers
   belongs_to :changesets
   validates_presence_of :user_id