The development and evolution of medical system in Japan was greatly influenced by Europe and America. But, the Japanese medical system hadn't been completely westernized in the Meiji Restoration period, or after World War II. The Japanese medical system not only absorbs the advanced Western experience, but also retains its own characteristics. This has a certain reference effect on China's medical reform. This paper traces the medical reform history in Japan during different periods, and sums up the characteristics of the medical reform in Japan: keep the medical tradition during the westernization process; the medical reform had never hampered people's lives; different medical institutions seek the balance during the medical reform.