Objective To explore the application value of End-tidal Carbon Dioxide Partial Pressure (PETCO2) monitoring in the quality and prognosis assessment of Cardiopulmonary Resuscitation (CPR) in emergency department, so as to provide a reference for clinical termination of CPR. Method A total of 62 patients suffered from cardiac arrest and admitted to the emergency department were divided into a return of spontaneous circulation group (ROSC group) of 32 cases and a non return of spontaneous circulation group (non-ROSC group) of 30 cases according to their resuscitation results, and their general information and PETCO2 values at different time points were compared between the two groups. Then the patients in the ROSC group were divided into a survival group and a death group according to their survival conditions at 7 days and 28 days after resuscitation, and the PETCO2 values at different time points were compared betweenthe two groups. Finally, the ROC curve was plotted and the optimal cutoff values predicting ROSC, 7 days and 28 days survival rates were obtained according to the Youden index. Results There were statistically significant differences in the place of onset, duration of CPR, cumulative doses of epinephrine and 5% sodium bicarbonate between the ROSC group and the non-ROSC group (all P<0.05), and there were statistically significant differences in the PETCO2 values between the two groups at various time points after undergoing CPR for 10 min or longer (all P<0.05); when undergoing CPR within 30 min, the area under the ROC curve of ROSC predicted by PETCO2 value at 20 min of CPR was the largest (AUC=0.982, 95% CI:0.955-1.000), the optimal cutoff value was 16.5 mmHg, the sensitivity and specificity were 93.8% and 96.7% respectively, and the Youden index was 0.904. There were statistically significant differences in the PETCO2 values 〖HJ*3〗between the 7 days survival group and the death group after ROSC at the point of ROSC,15 min or longer of CPR (all P<0.05); at 20 min of CPR, PETCO2 predicted the largest area under the curve of 7 days survival rate after ROSC（AUC=0.882, 95%CI：0.739-1.000）, the optimal cutoff value was 30 mmHg, the sensitivity and specificity were both 83.3%, and the Youden index was 0.667.There were statistically significant differences in the PETCO2 values between the 28 days survival group and the death group after ROSC at the point of ROSC,10 min or longer of CPR(all P<0.05); at 50 min of CPR, PETCO2 predicted the largest area under the curve of 28 days survival rate after ROSC（AUC=0.893, 95%CI：0.764-1.000),the optimal cutoff value was 27.5 mmHg, the sensitivity and specificity were 100% and 73.3% respectively, and the Youden index was 0.733. Conclusion PETCO2 monitoring can guide emergency nurses to evaluate the quality of CPR in patients suffered from cardiac arrest, and can be used as an important indicator to predict the clinical outcomes of patients.