diff --git a/app/controllers/homework_attach_controller.rb b/app/controllers/homework_attach_controller.rb
index ae4e66d1c..a2d5ef456 100644
--- a/app/controllers/homework_attach_controller.rb
+++ b/app/controllers/homework_attach_controller.rb
@@ -606,7 +606,7 @@ class HomeworkAttachController < ApplicationController
       order_by = "created_at #{direction}"
     end
     @all_homework_list = HomeworkAttach.eager_load(:attachments,:user,:rate_averages).find_by_sql("SELECT * FROM (SELECT homework_attaches.*,
-        (SELECT stars FROM seems_rateable_rates WHERE rateable_type = 'HomeworkAttach' AND rateable_id = homework_attaches.id AND is_teacher_score = 1 AND stars IS NOT NULL ORDER BY updated_at DESC limit 0,1) AS t_score,
+        (SELECT stars FROM seems_rateable_rates WHERE rateable_type = 'HomeworkAttach' AND rateable_id = homework_attaches.id AND is_teacher_score = 1 AND stars IS NOT NULL AND stars > 0 ORDER BY updated_at DESC limit 0,1) AS t_score,
         (SELECT AVG(stars) FROM seems_rateable_rates WHERE rateable_type = 'HomeworkAttach' AND rateable_id = homework_attaches.id AND is_teacher_score = 0) AS s_score
         FROM homework_attaches WHERE bid_id = #{bid_id}
         ORDER BY #{order_by}) AS table1