diff --git a/app/controllers/homework_attach_controller.rb b/app/controllers/homework_attach_controller.rb
index f4ce2e2af..68b3af5a4 100644
--- a/app/controllers/homework_attach_controller.rb
+++ b/app/controllers/homework_attach_controller.rb
@@ -439,8 +439,8 @@ class HomeworkAttachController < ApplicationController
     homework = @homework
     is_teacher = @is_teacher ? 1 : 0
     #保存评分@homework.rate(@m_score.to_i,User.current.id,:quality, (@is_teacher ? 1 : 0))
-    rate = @homework.rates(:quality).where(:rater_id => User.current.id, :is_teacher_score => is_teacher).first
-    if @m_score && rate.stars != @m_score
+    if @m_score
+      rate = @homework.rates(:quality).where(:rater_id => User.current.id, :is_teacher_score => is_teacher).first
       if rate
         rate.stars = @m_score
         rate.save!