diff --git a/app/services/courses_service.rb b/app/services/courses_service.rb
index c0d3d2f83..09cc5d59d 100644
--- a/app/services/courses_service.rb
+++ b/app/services/courses_service.rb
@@ -382,7 +382,7 @@ class CoursesService
       end
       latest_bid_message = messages.first
       unless latest_bid_message.nil?
-        latest_course_dynamics << {:type => 2,:time => latest_bid_message.created_on,:message => '最近更新了留言'}#l(:label_recently_updated_message,:locale => current_user.language.nil? ? 'zh':current_user.language)}
+        latest_course_dynamics << {:type => 4,:time => latest_bid_message.created_on,:message => '最近更新了作业'}#l(:label_recently_updated_message,:locale => current_user.language.nil? ? 'zh':current_user.language)}
       end
       #每个作业中学生最后提交的作业
       homeworks = []