It is well known that the morphologic feature of coronary artery is variant as finger print. Left coronary artery is divided into the left anterior descending artery and circumflex artery and supplies almost left atrium, left ventricle and interventricular septum. Clinically, the morphologic features of number of branches and the length of the left main coronary artery are important. In Korea, there are few reports about morphologic study of the coronary artery, and the coronary angiogram and open heart surgery are common. Now the author studied the morphology of the proximal part of the left coronary artery in Korean 50 Adult cadavers and obtained the following results: 1. The length of the left main coronary artery is from 5 mm to 16 mm [mean 9.7 mm]. 2. The diameter of the proximal part of the left coronary artery is from 3.2 mm to 7.7 mm [mean 5.3]. 3. The features of the branching are bifurcation [58%] trifurcation [38%] and quadrifurcation [4%]. 4. The diameter of the left anterior descending artery is from 2.7 mm to 8.1 mm [mean 4.5] and circumflex artery from 2.1 mm to 6.2 mm [mean 3.9].