Objective To investigate the angiographic characteristics of coronary lesions in patients of different subgroups of unstable angina pectoris.Methods Coronary angiograms and clinical manifestations were analysed on 388 patients.Results Single-vessel disease was more common in new onset effort angina (69.64%) than in other subgroups (P<0.05); triple-vessel disease and left main coronary artery disease appeared more frequently in patients with rest angina than in other subgroups (72.34% and 27.66% respectively, P<0.05), so did complex lesions and type C lesions (36.07% and 60.64% respectively, P<0.05). More than half of the culprit lesions in post-infarction angina were subtotal or total occlusions (53.12%), being more frequently found in this than in other subgroups (P<0.05). Most of the patients with Prinzmetal variant angina had mild coronary lesions only. Coronary thrombi were found in 10.45% of the 388 patients; they were more frequent in patients with post-infarction angina (20.00%) than in the subgroups of new onset effort angina, aggravated effort angina and Prinzmetal variant angina (4.26%, 7.53% and 0% respectively, P<0.05). Coronary thrombi were also more frequent in patients with chest pain at rest (16.39%) than in the subgroups of new onset effort angina and Prinzmetal variant angina (P<0.05).Conclusions It is suggested that patients with angina at rest should be treated more intensively. Energetic anticoagulation treatment should be given to patients with post-infarction angina and angina at rest.