where can i buy chinese silk fabric in bejing or shanghai to take home

In Beijing, you may find many good stores with what you want at Qianmen Area or Wangfujing. At Wangfujing, I bought some at the famous Rui Fu Xiang. You may also have a try!

In Shanghai, it i suggested to try at Dongjiadu (Nanpu Bridge) and Shi Liu Pu. Or there are several stores at Nanjing Road for your choice.