diff --git a/app/views/layouts/_course_base_info.html.erb b/app/views/layouts/_course_base_info.html.erb
index afd82646a..d2cc0840d 100644
--- a/app/views/layouts/_course_base_info.html.erb
+++ b/app/views/layouts/_course_base_info.html.erb
@@ -61,9 +61,9 @@
   <% is_TE = get_user_member_roles_course @course, User.current, 9 %>
   <% is_ST = get_user_member_roles_course @course, User.current, 10 %>
   <% if !is_teacher && (is_TA || is_TE)  %>
-      <%= link_to '教师身份', switch_role_course_path(@course, :user_id => User.current.id, :curr_role => 10, :tar_role => (is_TA ? 7 : 9)), :class => "sy_btn_orange mr10 fl" %>
+      <%= link_to '教师身份', switch_role_course_path(@course, :user_id => User.current.id, :curr_role => 10, :tar_role => (is_TA ? 7 : 9)), :class => "sy_btn_orange mr10 fl", :title => "由学生身份切换至教师身份" %>
   <% elsif is_teacher && is_ST %>
-      <%= link_to '学生身份', switch_role_course_path(@course, :user_id => User.current.id, :curr_role => (is_TA ? 7 : 9), :tar_role => 10), :class => "sy_btn_orange mr10 fl" %>
+      <%= link_to '学生身份', switch_role_course_path(@course, :user_id => User.current.id, :curr_role => (is_TA ? 7 : 9), :tar_role => 10), :class => "sy_btn_orange mr10 fl", :title => "由教师身份切换至学生身份" %>
   <% end %>
   <% unless (is_teacher || is_TA || is_TE) %>
       <div id="join_in_course_header"><%= join_in_course_header(@course, User.current) %></div>