This dissertation consists of six chapters: The first four chapters trace the history of Japanese piano music; the fifth chapter is a conclusion; and the last chapter is a complete list of 3,000 Japanese piano compositions written since the first Japanese piano piece was composed in 1900. The response of Japanese composers to Western-style music from the Meiji Restoration to the present is analogous to a transfusion: Japanese composers have accepted Western music while maintaining their cultural identity in an ever changing environment. The introduction of Western music through public school education at the beginning of the Meiji-period changed the function of music in Japan before Japanese composers could react to it creatively. The way that Japanese Western-style music has developed parallels other aspects of cultural Westernization: importation; absorption; and recreation. The borrowed musical forms eventually were transformed by combining them with the original characteristics of Japanese traditional music. It has taken more than one hundred years for the complete absorption of Western music into Japanese culture. The level of piano playing in Japan had improved dramatically from 1950 to 1970, and this is reflected in piano compositions in Japan. The first chapter relates Japanese history to Western music up to the first Japanese piano piece, which was composed in 1900. It examines the importation and development of Western ideas and culture into Japan from the seventeenth century to the nineteenth century. The second chapter illustrates the flowering of vocal music which led the development of Western-style music in Japan from 1900 to 1926. The third chapter discusses piano music from the beginning of the Showa-period (1926-1989) to the end of World War II. In this period the level of Japanese compositions improved greatly and Japanese piano music entered the international stage. The fourth chapter concerns Japanese piano music in the post-war generation.