The close relationship between a harbor and its hinterland has long been recognized. The operation of a harbor can stimulate development of its hinterland, while the state of a harbor's hinterland, such as its size and degree of economic development, most certainly influence the operations of the harbor. These relationships are interactive and interdependent. Moreover, harbor operations can change in response to evolving functions of the harbor, which in turn will influence the interactions between the harbor and its hinterland. However, the functions of a harbor are also strongly dependent on socioeconomic conditions within the society at large and on specific government policies. This paper seeks to explore the nature of harbor-hinterland relationships with reference to the development of Pu-Dai Port, Taiwan, during the Japanese colonial regime (1895-1945) as a case study. We seek to analyze the functional changes of Pu-Dai Port and its interactions with its hinterlands under dramatic socioeconomic and government policy changes during the period of Japanese rule.