Surgical revascularization is very effective for the relief of chest pain, improvement of exercise tolerance and ventricular performance in certain ischemic heart diseases. Bypass graft angiography and native coronary angiography after coronary artery bypass graft(CABG) were required for the evaluation of graft patency, progression of the native coronary artery disease and to predict the prognosis of the patients after CABG. The cases included in this study involved 15 patients who underwent selective bypass graft angiography among 102 CABG cases. Thirty eight sites were bypassed by saphenous vein and two sites by internal mammary artery. The results were as follows: 1) The overall patency rate of the saphenous vein bypass graft was 76.3% and the two sites of the internal mammary artery bypass graft were both patent. 2) The patency rate of direct anastomosis was 86.2% and of sequential anastomosis, 44.4%. 3) In eight patients who underwent native coronary angiography, five patients showed progression of grafted coronary artery disease. Among them, two patients had accompanying progression of coronary artery disease in non-grafted vessels. 4) Follow up treadmill test performed in six patients showed improvement of exercise tolerance in all patients. 5) There was some increase in the ejection fraction of the left ventricle after CABG in six patients who received follow up left ventriculography.