To investigatethe significance of Tpeak-Tend interval (Tpe) in risk stratification of deceleration capacity of rate (DC) and heart rate deceleration runs (DRs) in patient with acute cononary syndroms (ACS).Methods In 275 patients with ACS, induding 173 patients with acute myocardial infarction (AMI), 102 patients with unstable angina pectoris (UAP) and 100 healthy controls were selected in this study. All case were measured with 24h dynamic electrocardiogram and 12 lead electrocardiograms, the value of DC, DR2, DR4 and DR8 were analyzed with dynamic electrocardiogram system. Tpe and the corrected Tpe、Tpe√￣RR were calculated by elcctrocardiogram. The differece DC, DR2, DR4, DR8, Tpe and Tpe√￣RR between the AMI group, the UAP group and the control group were campared before the treatment with the β receptor blockers and after the treatment with the β receptor blockers, the differece DC, DR2, DR4, DR8, Tpe and Tpe√￣RR between the AMI group and the UAP group were campared before the treatment with the β receptor blockers and after the treatment with the β receptor blockers, the differece DC, DR2, DR4, DR8, Tpe and Tpe√￣RR between the AMI group and the UAP group were campared the ventricular arrhythmia group and non-the ventricular arrhythmia group. The risk stratification according to DC and DRs, the differece Tpe、Tpe√￣RR between the AMI group and the UAP group were campared the high risk group、medium risk group and low risk group, the correlation of DC with Tpe and DR2、DR4、DR8 with Tpe were analyzed in the AMI group and the UAP group. Results The value of DC、DR4、DR8 in the AMI group and the UAP group were significantly lower than that of healthy control group before the treatment with the β receptor blockers (P＜0.01-0.001), and the value of Tpe, Tpe√￣RR in the AMI group and the UAP group were significantly higher than that of healthy control group before the treatment with the β receptor blockers (P＜0.01). The value of Tpe, Tpe√￣RR in the AMI group were significantly higher than that of the UAP group before the treatment with the β receptor blockers (P＜0.05). The value of DC, DR4 and DR8 after the treatment with the β receptor blockers were significantly higher than that before the treatment with the βreceptor blockers in the AMI group and the UAP group (P＜0.01-0.001). The value of Tpe and Tpe√￣RR were significantly lower than that before the treatment with the β receptor blockers (P＜0.001) .The value of DC, DR4 and DR8 in the ventricular arrhythmia group were significantly lower than that of the non-ventricular arrhythmia group in the AMI group and the UAP group (P＜0.01-0.001) ,and the value of Tpe、Tpe√￣RR were significantly higher than that of non-ventricular arrhythmia group in the AMI group and the UAP group (P＜0.01) .The risk stratification according to DC, the value of the Tpe and Tpe√￣RR in the high risk group were significantly higher than that of the medium risk group in the AMI group and the UAP group(P＜0.05), and its in the medium risk group were significantly higher than that of the low risk group in the AMI group and the UAP group (P＜0.01). The risk stratification according to DRs, the value of the Tpe and Tpe√￣RR in the high risk group were significantly higher than that of the medium risk group in the AMI group and the UAP group(P＜0.05), and its in the medium risk group were significantly higher than that of the low risk group in the AMI group and the UAP group (P＜0.01). DC, DR2, DR4 and DR8 with Tpe were significantly notable negatively correlated in the AMI group and the UAP group (P＜0.01). Conclusion DC、DRs and Tpe had notable negative correlation among the patient of ACS. DC, DRs and Tpe are a predictors in patient with ACS at high risk.