Ryukyu sent more than 20 batches of returned students to China for studying during the Ming and Qing Dynasties, many of whom were studying medicine. Liu qiu bai wen (One Hundred Question of Ryukyu) was the record of discussion between Cao Cunxin, a famous doctor of the Qing Dynasty, and the oversea disciples of Lü Fengyi from Ryukyu. However, it was not only a medical book, but also served as an important witness on overseas dissemination of TCM, and the fresh case of Chinese training medical talented persons for Ryukyu. Training Ryukyu medical students in the Qing Dynasty was good for the expansion of Chinese medicine in the Ryukyu, and promoted the development and social progress of the Ryukyu medicine and health, made a significant contribution to maintain the friendly relationship between the two countries.