Objective To investigate the diagnosis and prognosis of patients with coronary artery aneurysm in Kawasaki disease.Methods The data of ultrasonic diagnosis and follow-up of 338 children with Kawasaki disease complicated with coronary artery aneurysms were analyzed.Results The incidence of coronary artery aneurysm in the acute stage of Kawasaki disease was 21.2％ (338/1 594).Of all the 338 cases,small aneurysms was 66.6％ (225 cases),medium aneurysms was 25.1％ (85 cases),and giant aneurysms was 8.3％ (28 cases).There were 719 branches involved in 338 cases,32.8％ of them in left main coronary artery and 31.1％ in right coronary artery;25.3％ in left anterior descending branch,and 10.8％ in left circumflex branch.A total of 382 branches were followed up,including 218 branches of small coronary aneurysm group and 82.1％ of them were completely recovered to the normal diameter.The medium aneurysm group was 124 brunches,the proportion of no significant change,retraction,and normal were 23.4％,68.5％ and 8.1％,respectively.There were 40 brunches in the giant anuerysm group,in which the proportion of no significant change,retraction,and normal were 70.0％,27.5％ and 2.5％,respectively.A total of 30 thrombosiswere detected by echocardiography in the acute stage,20 thrombosis were regularly followed up,12 thrombosis gradually subsided,and the other remained persist.Five thrombosis were detected in the sequelae stage,and all located in the giant coronary aneurysm.Seven children were clinically diagnosed with ischemic heart disease,of them,acute myocardial infarction in 1 case,1 died of heart failure.Conclusions Kawasaki disease coronary artery disease are common in small coronary aneurysms,of which the left main artery and right coronary artery lesions are the most common,and the prognosis is better;medium and giant aneurysm need more time to recovery,and are easy to complicated with thrombosis.