It's very kind of you,and your reply helps me much!!
thank you

Quote Originally Posted by RescoCCC View Post
You must enter the unique product identifiers on the product setup page. If you don't, the feed cannot populate those attributes. Two out of three are required. The categories are brand, (same as products manufacturer), MPN, (same as product model), and GITN, which includes stuff like UPC, ISBN, etc.

For Google Product Category you must select the appropriate category from the Google Taxonomy and enter the information in the Google Merchant Center Feeder Configuration on the line that reads Default Product Category.

For example, one of my sites is collectibles so I used the Google Taxonomy of Arts & Entertainment > Collectibles. The entry on that line is done as Arts & Entertainment > Collectibles.