diff --git a/app/helpers/courses_helper.rb b/app/helpers/courses_helper.rb
index 138f88d53..36eebe4f2 100644
--- a/app/helpers/courses_helper.rb
+++ b/app/helpers/courses_helper.rb
@@ -751,7 +751,7 @@ module CoursesHelper
   #加入课程、退出课程按钮
   def join_in_course_header(course, user, options=[])
     if user.logged?
-      joined = course.members.map{|member| member.user_id}.include? user.id
+      joined = course.members.includes(:user).map{|member| member.user_id}.include? user.id
       text = joined ? l(:label_course_exit_student) : l(:label_course_join_student)
       url = joined ? join_path(:object_id => course.id) : try_join_path(:object_id => course.id)
       method = joined ? 'delete' : 'post'
diff --git a/app/views/layouts/_project_info.html.erb b/app/views/layouts/_project_info.html.erb
index 461d2b6d9..1f40c24ad 100644
--- a/app/views/layouts/_project_info.html.erb
+++ b/app/views/layouts/_project_info.html.erb
@@ -1,13 +1,13 @@
 <% is_teacher = User.current.logged? && (User.current.admin? || User.current.allowed_to?(:as_teacher,@course)) %>
-<% teacher_num = TeacherAndAssistantCount(@course) %>
-<% student_num = studentCount(@course) %>
+<% teacher_num = 0 %>
+<% student_num = 0 %>
 <div class="pr_info_logo fl mr10 mb5">
   <% if is_excellent_course(@course) %>
     <img src="/images/course/boutique.png" width="50" height="auto" alt="精品" class="boutiqueP" />
   <% end %>
 <%= image_tag(url_to_avatar(@course), :width => "60", :height => "60") %>
 </div>
-<div class="pr_info_id fl mb5 f14">ID:<%= @course.id%><%= @course.is_public == 0 ? "（私有）" : "（公开）" %>
+<div class="pr_info_id fl mb5 f14">ID:<%= @course.id %><%= @course.is_public == 0 ? "（私有）" : "（公开）" %>
   <% if is_excellent_course(@course) %>
     <img src="/images/course/medal.png" alt="精品课程" style="vertical-align:bottom;" class="ml5" />
   <% end %>