diff --git a/app/views/asks/index.html.erb b/app/views/asks/index.html.erb
index 2bf2709..240211a 100644
--- a/app/views/asks/index.html.erb
+++ b/app/views/asks/index.html.erb
@@ -128,7 +128,7 @@
         <input id="history_email_id" type="text">
       </div>
       <div>
-        <label for="history_ticket_number"><%= t("ask.ticket_number") %></label>
+        <label for="history_ticket_number"><%= t("ask.serial_number") %></label>
         <input id="history_ticket_number" type="text">
       </div>
       <div>
diff --git a/config/locales/en.yml b/config/locales/en.yml
index dd96545..2242bce 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -24,7 +24,7 @@ en:
     apply_all: "Apply All"
     discard_changes: "Discard Changes"
     default_custom_fields: "Default custom fields"
-    serial_number: "No."
+    serial_number: "Ticket No."
     the_same_as_field_name: "The same as Field Name"
     recover_data: "Recover Data"
     are_you_sure_to_recover_data: "Are you sure to recover data?"