Since the Japanese colonization,ulcornerThe Architectural Association of Chosun(AAC)ulcornerwas founded by the Japanese architects residing in Chosun. It is necessary to study the house related activities of this AAC as the process of modernization of Korean houses. As research materials,ulcorner Chosun and Architectureulcornerwas used and the main concern of this research was based on competition of house design which were published in the magazines. There were four competitions which reflected the activity background of AAC with the social circumstances at that time and the research was done especially on the definite situation of the competition of house design. Also, the prize winning works were analyzed accordingly.