This chapter addresses the development of architecture in Japanese colonial Taiwan and asserts its role in terms of the modernity in Taiwan. The definite attitude of the Taiwanese people towards the architecture built in the Japanese colonial period resulted in the positive preservation of such architecture as cultural heritage. Japan began its political governance of Taiwan in 1895. "City improvement" is the method that Japanese adopted in the early stage of the urban transformation. Taiwan's cities were developed in a manner closer to that of Western cities. When compared with the Western historical, style architecture, modern architecture has fewer decorations and more richly built form and spatial organization. The development of the Kingo Tatsuno style reached its climax in the new Office of the Governor-General, which is the most symbolic building of the Japanese Period at both the architectural and political levels. The Governor-General's Office was the most powerful authority in the Japanese colonial government in Taiwan.