[CHENG Dan-an's experience of study in Japan].

The first hand documents, the process and achievements of Mr. CHENG' s study in Japan in the 1930s were investigated in order to provide basic information to explore the original academic thoughts of Mr. CHENG and the Chengjiang Acupuncture School. It was concluded that the experiences of Mr. CHENG's study in Japan had significant influence on enriching and developing his academic thoughts. It has not only enhanced his confidence in therapeutic effect of moxibustion and revival of Chinese acupuncture, but also established the foundation for the reform of needles and expansion of the domain of Chinese acupuncture and its development after returning home.