Traditional Chinese Medicine (TCM), one of China's splendid cultural heritages, is the science dealing with human physiology, pathology, diagnosis, treatment and prevention of diseases. With the development of modern science, people come to consider the way of the moderniation of TCM. Recently, many researchers mainly in China attempt to realize Diagnosis in TCM based on Artificial Neural Networks (DTCMANN). This paper aims at providing an overview of recent DTCMANN studies in TCM field, and focuses on the introduction and summarization of the existing research work about DTCMANN. A review of five major situations, where DTCMANN approaches are applied, has been presented For each situation, the DTCMANN approaches employed are outlined as well as the corresponding results. Current research on DTCMANN shows that it is both feasible and promising, and that it is still nearly a piece of virgin soil. The future research direction of DTCMANN is also pointed out based on a discussion of the existing research work.