【Abstract】Objective To analyze the APACHE score and risk factors in patients under continuous renal replacement therapy (CRRT), and to investigate the clinical application of acute physiology and chronic health evaluation (APACHE) scoring in CRRT patients. Subjects and method We studied the severe patients under CRRT in the departments of Shanghai Ruijin Hospital Affiliated to Shanghai JiaoTong University, School of Medicine in 2006. Their APACHE II and III scores were calculated 24 hours before CRRT, and their coefficient of mortality risk was also estimated. SPSS 15.0 was used for statistics. Measurement data was showed as X±S, Chi-square test was used for the comparison of ratios, and one sample t-test was used to compare the data among different groups. P<0.05 was considered to be significant. Multinomial logistic regression was applied to explore the risk factors. Results A total of 113 severe patients under CRRT were collected. Their age ranged 60.42±17.44 yrs, and the male to female ratio was 74/39. Forty-seven patients were treated in ICU, and 66 were treated outside ICU. Forty-seven cases survived, and the mortality rate was 58.4%. The average APACHE II score was 26.3±7.7, and the coefficient of mortality risk was 0.47±0.26. The APACHE II score was 29.2±8.1 and 22.4±4.8 (P<0.001) in death and survival groups, respectively. The average APACHE III score was 91.4±29.0, and the coefficient of mortality risk was 0.77±0.27. The APACHE III score was 104.7±28.6 and 72.3±16.6 (P<0.001) in death and survival groups, respectively. Logistic regression analysis showed that mechanical ventilation (P=0.000), hyperbilirubinemia (P=0.022) and hypotension (P=0.030) were the risk factors affecting the prognosis of CRRT patients. Conclusion The prognosis of CRRT patients was closely correlated to APACHE score, and the score was significantly different between death and survival groups. APACHE scoring can be applied to predict mortality of CRRT patients earlier.