diff --git a/app/models/bid.rb b/app/models/bid.rb
index bc00a8460..88014477b 100644
--- a/app/models/bid.rb
+++ b/app/models/bid.rb
@@ -28,6 +28,7 @@ class Bid < ActiveRecord::Base
   has_many :homework_for_courses, :dependent => :destroy
   has_many :courses, :through => :homework_for_courses, :source => :course
   has_many :homeworks, :class_name => 'HomeworkAttach', :dependent => :destroy
+  has_many :homework_evaluations, :through => :homeworks
   has_many :join_in_contests, :dependent => :destroy
   has_many :praise_tread, as: :praise_tread_object, dependent: :destroy
   # has_many :fork_homework, :class_name => 'Bid', :conditions => "#{Bid.table_name}.parent_id = #{id}"
diff --git a/app/models/homework_attach.rb b/app/models/homework_attach.rb
index 99d540bd1..e18e254cb 100644
--- a/app/models/homework_attach.rb
+++ b/app/models/homework_attach.rb
@@ -10,6 +10,7 @@ class HomeworkAttach < ActiveRecord::Base
   has_many :users, :through => :homework_users
   seems_rateable :allow_update => true, :dimensions => :quality
   belongs_to :project
+  has_many :homework_evaluations, :dependent => :destroy
   
   safe_attributes "bid_id",
 				  "user_id"
diff --git a/app/models/homework_evaluation.rb b/app/models/homework_evaluation.rb
new file mode 100644
index 000000000..ccbd26f8c
--- /dev/null
+++ b/app/models/homework_evaluation.rb
@@ -0,0 +1,6 @@
+class HomeworkEvaluation < ActiveRecord::Base
+  attr_accessible :homework_attach_id, :user_id
+
+  belongs_to :homework_attach
+  belongs_to :user
+end
diff --git a/app/models/user.rb b/app/models/user.rb
index 0bb359812..bbee7f763 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -75,6 +75,7 @@ class User < Principal
 
   has_many :homework_users
   has_many :homework_attaches, :through => :homework_users
+  has_many :homework_evaluations
 
   has_and_belongs_to_many :groups, :after_add => Proc.new {|user, group| group.user_added(user)},
                                    :after_remove => Proc.new {|user, group| group.user_removed(user)}
diff --git a/db/migrate/20141031111632_create_homework_evaluations.rb b/db/migrate/20141031111632_create_homework_evaluations.rb
new file mode 100644
index 000000000..39b65a033
--- /dev/null
+++ b/db/migrate/20141031111632_create_homework_evaluations.rb
@@ -0,0 +1,10 @@
+class CreateHomeworkEvaluations < ActiveRecord::Migration
+  def change
+    create_table :homework_evaluations do |t|
+      t.string :user_id
+      t.string :homework_attach_id
+
+      t.timestamps
+    end
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 4d194b54e..3961db258 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20141029065917) do
+ActiveRecord::Schema.define(:version => 20141031111632) do
 
   create_table "activities", :force => true do |t|
     t.integer "act_id",   :null => false
@@ -478,6 +478,13 @@ ActiveRecord::Schema.define(:version => 20141029065917) do
     t.integer  "project_id",  :default => 0
   end
 
+  create_table "homework_evaluations", :force => true do |t|
+    t.string   "user_id"
+    t.string   "homework_attach_id"
+    t.datetime "created_at",         :null => false
+    t.datetime "updated_at",         :null => false
+  end
+
   create_table "homework_for_courses", :force => true do |t|
     t.integer "course_id"
     t.integer "bid_id"