diff --git a/app/models/patent.rb b/app/models/patent.rb
index 063fac1..b3b467b 100644
--- a/app/models/patent.rb
+++ b/app/models/patent.rb
@@ -4,7 +4,7 @@ class Patent
   include OrbitModel::Status
   include Slug
 
-  belongs_to :patent_type
+  has_and_belongs_to_many :patent_types
   belongs_to :member_profile
 
   field :patent_title, as: :slug_title, localize: true
@@ -18,6 +18,7 @@ class Patent
   field :publish_date , :type => Date
   field :url
   field :note
+  field :rss2_id
   field :create_user_id, :type => BSON::ObjectId
   field :update_user_id, :type => BSON::ObjectId
 
diff --git a/app/models/patent_type.rb b/app/models/patent_type.rb
index e5e90f4..8202881 100644
--- a/app/models/patent_type.rb
+++ b/app/models/patent_type.rb
@@ -4,6 +4,6 @@ class PatentType
   
   field :title, localize: true
 
-  has_many :patents
+  has_and_belongs_to_many :patents
   
 end
\ No newline at end of file
diff --git a/app/views/admin/patents/_form.html.erb b/app/views/admin/patents/_form.html.erb
index c39dac7..85ce1f0 100644
--- a/app/views/admin/patents/_form.html.erb
+++ b/app/views/admin/patents/_form.html.erb
@@ -53,7 +53,9 @@
       <div class="control-group">
         <label class="control-label muted"><%= t("personal_patent.patent_category") %></label>
         <div class="controls">
-          <%= f.select :patent_type_id, @patent_types.collect {|t| [ t.title, t.id ]} %>
+          <% @patent_types.each do |pt| %>
+            <input type="checkbox" name="patent[patent_type_ids][]" value="<%= pt.id.to_s %>" <%= (@patent.patent_type_ids.include?pt.id) ? "checked=checked" : "" %> /> <%= pt.title %>
+          <% end %>
         </div>
       </div>