The origin of three image hall pattern of the early Buddhist architecture was often discussed but not clearly identified. The paper intend to criticize a few theories proposed earlier and to establish a new possibility that could be summerized as followings : 1) During the fourth century the inclusion of image halls on each side of the pagada was modeled after the paird buildings of East & West Hall on each side of the Central Hall which was the new development of contemporary palace architecture. 2) This could have resulted the pattern of two image halls as the beginning stage of three image hall pattern as can be traced by the excavated sites of Koguryo such as ChongRung-sa.
