Both coronary arteriography (CAG) and myocardial emission computed tomography (ECT) were performed in 58 patients. According to CAG findings and clinical manifestations, 47 patients were diagnosed as coronary heart disease (CHD), while 11 not. CAG was abnormal in 39 patients of the 47. The sensitivity and specificity of CAG were 83% and 100% respectively. The diagnosis of CHD was made without any doubt in patients with abnormal CAG. The sensitivity of ECT was 97.9%, the specificity only 45.5%, and the predictive value of negative ECT 83.3%. Therefore, abnormal ECT should be closely related to the clinical manifestations in order to evaluate its significance and a normal ECT may rule out CHD with more reliability.