diff --git a/app/controllers/desktop/co_authors_controller.rb b/app/controllers/desktop/co_authors_controller.rb
index 5b871bd9..c027a162 100644
--- a/app/controllers/desktop/co_authors_controller.rb
+++ b/app/controllers/desktop/co_authors_controller.rb
@@ -1,6 +1,7 @@
 class Desktop::CoAuthorsController < ApplicationController
   def index
     @co_authors = CoAuthor.where(name_id: current_user.id)
+    @co_author_relations = CoAuthorRelation.all
 
     respond_to do |format|
       format.html { render :layout => false}
@@ -27,6 +28,7 @@ class Desktop::CoAuthorsController < ApplicationController
 
   def edit
     @co_author = CoAuthor.find(params[:id])
+    @co_author_relations = CoAuthorRelation.all
     respond_to do |format|
       format.html { render :layout => false}
     end
diff --git a/app/models/user/co_author.rb b/app/models/user/co_author.rb
index 9bcaf7d6..4c662acb 100644
--- a/app/models/user/co_author.rb
+++ b/app/models/user/co_author.rb
@@ -6,9 +6,8 @@ class CoAuthor
   field :name_id, type: BSON::ObjectId
   field :co_author, localize: true
   field :email
-  field :type
 
-  has_and_belongs_to_many :co_author_relations
+  belongs_to :co_author_relations
 
   VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/
   validates :email, format: { with: VALID_EMAIL_REGEX },
diff --git a/app/views/desktop/co_authors/_form.html.erb b/app/views/desktop/co_authors/_form.html.erb
index 3628dff3..b087be95 100644
--- a/app/views/desktop/co_authors/_form.html.erb
+++ b/app/views/desktop/co_authors/_form.html.erb
@@ -17,7 +17,7 @@
 
 
   <%= f.label :type%><br />
-  <select name="co_author[type]" id="" class="s_grid s_grid_4">
+  <select name="co_author[co_author_relations_id]" id="" class="s_grid s_grid_4">
     <%= options_for_select(
       @co_author_relations.map do |relation|
         [relation.relation, relation.id]
diff --git a/app/views/desktop/co_authors/index.html.erb b/app/views/desktop/co_authors/index.html.erb
index e8e424d2..b01b2569 100644
--- a/app/views/desktop/co_authors/index.html.erb
+++ b/app/views/desktop/co_authors/index.html.erb
@@ -17,7 +17,8 @@
   <tr>
     <td><%= co_author.co_author %></td>
     <td><%= co_author.email %></td>
-    <td><%= co_author.type%></td>
+    <td><%= @co_author_relations.find(co_author.co_author_relations_id).relation \
+                unless co_author.co_author_relations_id.nil?%></td>
     <td><%= link_to 'Edit', edit_desktop_co_author_path(co_author), :class => "bt-edit" %></td>
     <td><%= link_to 'Destroy', desktop_co_author_path(co_author), method: :delete, confirm: 'Are you sure?', :class=>"bt-delete"  %></td>
   </tr>
diff --git a/db/seeds.rb b/db/seeds.rb
index 00825e32..9c90554c 100644
--- a/db/seeds.rb
+++ b/db/seeds.rb
@@ -2,8 +2,9 @@ require 'factory_girl'
 require 'faker'
 require 'json'
 
-WritingJournal.destroy_all
 CoAuthor.destroy_all
+CoAuthorRelation.destroy_all
+WritingJournal.destroy_all
 
 data = File.read("db/data")
 data_json = JSON.parse(data)
@@ -16,13 +17,21 @@ name_en = name_en.map do |p| Faker::Name::name end
 email = Array.new 51,""
 email= email.map do |p| Faker::Internet.email end
 
-type = ["friend", "teacher", "student", "mate", "relation"]
+type = ["friend0", "teacher0", "student0", "mate0", "relation0", "friend1", "teacher1", "student1", "mate1", "relation1"]
+
 FactoryGirl.define do
+  factory(:type, class: "CoAuthorRelation") do |f|
+    f.sequence(:relation_translations) do |n|
+      { zh_tw: "#{type[n%type.size]}",
+            en: "#{type[n%type.size]}" }
+    end
+  end
+
   factory(:co_author_candidate, class: "CoAuthor")  do |f|
 
     f.sequence(:co_author_translations) do |n|
       { zh_tw: "#{name_tw[n]}",
-            en: "#{name_en[n]}" }
+        en: "#{name_en[n]}" }
     end
     f.sequence(:type) do |n| "#{type[n%5]}" end
     f.sequence(:email) do |n| "#{email[n]}" end
@@ -81,6 +90,9 @@ FactoryGirl.define do
   end
 end
 
+10.times.each do
+  FactoryGirl.create(:type)
+end
 
 50.times.each do
   FactoryGirl.create(:paper_record)
@@ -89,3 +101,4 @@ end
 50.times.each do
   FactoryGirl.create(:co_author_candidate)
 end
+