The purpose of Ihis study is tO clarify the effect that the ceiling height difference of a room have on perception of room vo 夏 ume and spatial impressions , The various width and position of the ceiling height difference of a room is presented randomly , In し he first experiment , The Method of Magnitude Estimatien is used ;subjects are then compared the volumes of high − cei 且 inged area and of 且 ow − ceninged area . In the second experirnent , subjects are then asked spatial impressions on 4 items ( i. e , how many spaces are perceived , which space is felt as the main space , fee皿 ing of comfortab 置 eness , sense of opPr6ssion ) . Subjects are experienced the experimental room in standing amd reclining pestures . The resu 脆s are summarized as below ; 1) Perception of room volume and spatial impressions has highly corre 且 ated with Ihe widlh and position of the ceiling heighI