The indication in revascularization surgery is quite complicated, as the manifestation of the anatomical disease in the major three coronary arterial trees are innumerable and different as the face of each patient. Even though it is simply grouped into three categories as single, double and triple vessel disease, the combination of the degree and position of the obstructive lesions and the status of left ventricular function is varied in each instance. Adding further the patient's specific variables and risk factors to the anatomical variance, the situation becomes more complex. During the first decade of revascularization surgery, several large scale clinical studies were carried out in the United States and Europe to define the subsets of patients who were more benefited by revascularization surgery than medical treatment. The technique of aorto-coronary bypass graft (CABG) surgery also rapidly developed during this period and more complete revascularization using more durable conduits such as the internal mammary artery grafts with less surgical morbidity and mortality has been attained in the second decade. The appearance of PTCA (percutaneous transluminal coronary angioplasty) as a new invasive modality of treatment by the cardiologist towards the end of 1970's further complicated the indication of CABG. The comparative benefit of PTCA & CABG should be searched by the objective prospective randomized studies but such studies may be very difficult to be conducted in large scale, and meantime the number of PTCA will continue to increase. Based on the ACC/AHA Task Force Report, "Guideline and Indication for Coronary Artery Bypass Graft Surgery.": JACC Vol. 17, No. 3 March 1, 1991: 543-89, some of the subjects in surgical treatment of coronary artery disease were discussed in this paper.