After medical insurance came into effect in Korea, health care system has undergone tremendous changes. Changing patterns of newly established clinics is one of them. To investigate changes and trends, a total of 10,184 clinics which were newly established from 1981 to 1990 were analysed. Data were obtained from the file of contracting medical facilities of the Federation of Medical Insurance Societies. The proportion of newly establishied clinics has increased gradually, so that they amount to 13% of the total medical facilities in Korea. Meanwhile, the number of newly established medium-size hospitals and general hospitals have decreased. The number of newly established clinics per 100, 000 populations has increased in the all areas, but the rate of increase has decreased in the cities except in 6 major cities in 1990. The rate of increase in newly established clinics surpasses that of population increase. This study has identified the trend of young physicians' early driving into their solo medical practice than before. This indicates chance of the medical specialty training nowadays toughen due to the limited openings in residency programs. However, the sex ratio of physicians at newly established clinics has not changed. The decreasing tendency to open medical practice without beds and the increasing size of clinics are found in this study(The size has been measured in terms of medical manpower, of beds, and of medical equipment in this study). Two thirds of general practitioners have opened their clinics without beds, although such trend has been less in the case of specialists. All three indicators show increasing size, especially in the case of rural clinics. However, among them, the number of medical equipments has increased most significantly from 8.9 items in 1981 to 12.9 in 1990.