diff --git a/app/controllers/weapps/courses_controller.rb b/app/controllers/weapps/courses_controller.rb
index ccd5d1bcf..a0ee59971 100644
--- a/app/controllers/weapps/courses_controller.rb
+++ b/app/controllers/weapps/courses_controller.rb
@@ -20,6 +20,7 @@ class Weapps::CoursesController < Weapps::BaseController
 
     activities = @course.course_activities.where("course_act_type in ('Course', 'CourseMessage') or
                   (course_act_type = 'HomeworkCommon' and course_act_id in #{homework_ids})").order("id desc")
+    @activities_count = activities.size
     @activities = paginate activities.includes(:course_act, user: :user_extension)
   end
 
diff --git a/app/views/weapps/courses/course_activities.json.jbuilder b/app/views/weapps/courses/course_activities.json.jbuilder
index 498189cf8..edef01e1d 100644
--- a/app/views/weapps/courses/course_activities.json.jbuilder
+++ b/app/views/weapps/courses/course_activities.json.jbuilder
@@ -9,4 +9,5 @@ json.activities @activities do |activity|
   json.created_at activity.created_at.strftime('%m-%d %H:%M:')
   json.container_name activity.container_name
   json.container_type activity.course_act_type == "HomeworkCommon" ? activity.course_act&.homework_type : ""
-end
\ No newline at end of file
+end
+json.activities_count @activities_count
\ No newline at end of file