Abstract: Objective To investigate the diagnose value of dynamic electrocardiogram(ECG)on ischemic heart disease. Methods Thirty-two cases aged more than 40 years old with chest tightness were chosen,and atrioventricular block were found after dynamic ECG checking. Twenty-eight cases among them were examined by coronary artery angiography. Results Coronary artery angiography examination of 28 patients showed that 12 cases(42.8%)with right coronary artery posterior descending artery clogging by 70%, 8 cases with right coronary artery posterior descending artery clogging by 30% to 50%,3 cases with left circumflex coronary artery clogging by 50%,3 cases with negative coronary artery angiography. Conclusion Coronary artery clogging can be mostly found in the patients with atrioventricular block aged more than 40 years old who were suffered from chest tightness. A coronary artery angiography examination should be taken for diagnosing.