This paper aims to explore the state of activities of architects in modern Hiroshima. Based on the sufficient understanding to modern architectures, their designers and designing organizations of pre-war Hiroshima, this study tends to clarify the features of the activities of those architects who were in Hiroshima during Taisho period and the earlier stage of Showa period. The results of this study are: Before being bombarded, the mainstream of architects' activities in Hiroshima was of those non-local architects, particularly,(1) activities of architects by utilizing Trust System in earlier stage of Showa;(2) building institutions of Guan Gong Sheng Ting and the activities of architects;(3) moreover, a series of bank buildings, with the involvement of famous architects, such as Kingo Tatsuno and Uheiji Nagano, and by their respective single piece of work, contribute a lot in the history of architecture of modern Hiroshima. In addition, up to now, little has been known about the activities of folk architects or non-government building institutions. And the pieces of work from local building institutions are few as well.