This study was performed to investigate the practical oriental medical expenses by the use of internal data of an oriental hospital due to the bias of medical insurance program data. The purpose of this study was to describe prevalent diseases of clinical department in the studied hospital, to analyze medical expenses structure and to verify the each cost share ration of expenses on insurer to insuree. Under this purpose, we analyzed actual medical expenses data of 1,611 hospitalized patients of the oriental medical university hospital with 150 beds that can be approached to internal data from Jan. 1, 1994 to Dec. 31, 1994. The major findings are as follows : 1. Upper five of most frequent diseases of admitted patients were Joul-Jung-Pung(55.5%), Yoo-Kak-Tong(7.3%), Yoo-/Tong(7.1%), Gu-An-Wa-Sa(2.7%) and sequale of Joul- Jung-Pung(2.4%) 2. In medical expenses structure, hospital ward fee was 47.1%, medication fee 41.3%, fee for procedure(acupuncture, moxibustion, negative therapy, physical therapy, etc) 11.1% and consultation fee 0.5%. In addition to the cost share ration of insuree & that of insurer was 75:25 respectly.