Chinese grammar
Ma is the author of "Mashi Wentong" (馬氏文通 "Basic principles for writing clearly and coherently by Mister Ma"), the first textbook of Chinese grammar written by a Chinese (there were already several grammars written by Westerners), published in 1898. Today most scholars believe that Ma's older brother Ma Xiangbo, a famous educator and co-founder of Fudan University, also contributed to the work.