In the development of medical care of Taiwan, western medical system has played a critical role. However, a closer examination of Taiwan medical history showed that the influence of western medicine on Taiwan is only about a hundred years. It indicated that the development of Taiwanese medical care system is affected not only by the western, medicine but a number of other systems. Exploring the complex interactions of different systems, the present study disclosed three medical systems in the mainstream of Taiwanese medical care development during pre-Japan-occupied era, namely, witch medicine, Chinese medicine, and western medicine. In addition, by tracing their influences, the present study pointed out that the western medicine supported by the Japanese government then emerged as the most powerful force in its colony, Taiwan. Consequently, it became the landmark of the modern history of Taiwan medical care as a result of medical and political interplay.