This paper explores the possibility of evaluating the English abilities of the Chinese people who engaged in Sino-foreign trade in Canton and Macau in the 18^th and 19^th centuries. Making use of an English letter written in the name of the Hong merchant Puankhequa and another one by Whang Tong，possibly a compradore who spent his earlier days in England，as well as a journal written by a Boston captain who travelled to Canton a number of times before the treaty days，the author tries to demonstrate how correspondence and oral conversation between Chinese and foreigners were made possible. She also suggests that with more and more source materials become available，the study of Pidgin English should be seen in a new light.