The present study aimed to compare and analyze the particulars of and difference in medical expenses and their composition ratio for 2,026 patients hospitalized at 2 types of medical institutions (443 at a clinic and 1,583 at a hospital) in Jeonju-si, Jeollabuk-do under coverage of automobile insurance during 2009. From the analysis, it became evident that there were differences in individual characters of inpatients covered by automobile insurance, and details, composition and composition ratio of medical treatment for them depending on types of medical institutions. There was no difference, however, between the total and average medical expenses per capita even when markup rate was applied to the automobile insurance by types of hospitals. The ratio of radiotherapy and physical therapy in the composition of medical expenses was found to be extraordinarily high in clinics compared to that of hospitals. The composition ratio of the fixed cost including charge for hospitalization also turned out to be fairly high in all medical institutions.