Open heart surgery begun at 1959 in Korea. From that time to 1979, the surgery was performed below 100 cases in a year. However,that was performed above, 1,000 cases in a year from 1981. During the recent three years, i.e., 1985, 1986, and 1987, the annual operative cases were 3614,4503, and 4906, and then the mortality rates were progressively decreased to 6.2%, 5.3 %, and 5.0 %. In these time, overall mortality rate above 1 year old was 5.0 % versus that below 1 year old 17.9 9o in congenital heart diseases. These results are statistically different between two groups. Of the valvular heart disease cases, which occupied 97 % of total acquired heart disease, individual incidence was in mitral 68 %, and aortic 28%. The operative method was mainly valve replacement. Operative mortality for valve surgery in total was 4.4 %. Until 1985, bioprosthetic valve was frequently implanted but mechanical valve has been done more frequently in these days. Coronary artery bypass graft was large portion [67 * 75 %] of open heart surgery in western, but was below 1 % in Korea. However our diet patterns have been changed. Therefore we think the incidence of coronary artery disease will be increased. So we will be familiar to this field.