This is a card (not a postcard) commemorating the opening of the China Stamp Agency in North America in 1981. The attached stamp is titled "Amphora with Apricot Blossom." It is one in a series of six Chinese Ceramics stamps issued April 15, 1981.
The China Stamp Agency in North America is now found at http://www.stampagencies.com/, along with stamp agencies for some other countries.
This stamp is the most colorful one in the series:
This is a post for Sunday Stamps at Viridian's Postcard Blog