Objective To further recognize the coronary artery three vessel disease by studying the abnormal change of the electrocardiogram(ECG)and echocardiography of ischemic heart disease patients and unstable angina pectoris patients,and to analyze the results of coronary angiography.Methods Coronary arteriography for 2 654 patients diagnosed as ischemic heart disease,unstable angina pectoris,were conducted and the result of coronary arteriography were compared with the ECG and echocardiography.Results There were certain statistically significant correlation among the ECG,echocardiography abnormal change and three vessel coronary artery disease(ECG:χ2 =9.02,P <0.01;echocardiography:χ2 =14.36,P <0.01).The sensitivity,specificity,false positive rate,and false negative rate of ECG were 71.46%,27.47%,62.26% and 28.50% respectively.The sensitivity,specificity,false positive rate, and false negative rate of echocardiography were 61.27%,27.08%,72.91% and 38.72% respectively.ECG′s change of patients appear in 8 or more leads when angina pectoris attacks exist,the incidence of chest lead terminal positive T wave were higher than 90.00%.Ⅲ lead fQRS wave group or low voltage changeed and AVR lead ST seg-ment elevation were accounting for 82.61% and 56.52% respectively.Conclusion There are certain correlation and predictive value among the ECG,echocardiography and three vessel coronary artery disease.There are characteristic waveform change of ECG when angina pectoris attacks exist.