Objective To study the risk factors of acute kidney injury(AKI)secondary to the decompensated stage of chronic hepatitis B(CHB)cirrhosis.Methods A total of 316 patients with decompensated CHB cirrhosis diagnosed and treated in the Affiliated Hospital of Shaoxing University of Arts and Sciences from January 2018 to January 2024 were divided into CHB cirrhosis decompensated group(CHBCD group,n=72)and CHB cirrhosis decompensated secondary AKI group(CHBCD+AKI group,n=244).Compare the differences in clinical data between two groups of patients.Spearman rank correlation analysis detects the correlation between indicators and serum creatinine(Scr)and blood urea nitrogen(BUN).Multivariate Cox regression analysis of risk factors for AKI secondary to CHB cirrhosis.Effectiveness of receiver operating characteristic curve were analyzed in predicting AKI secondary to CHB cirrhosis.Kaplan-Meier survival model and Log rank were used to compare the difference in survival time between two groups of patients.Results The hepatic encephalopathy rate,prothrombin time(PT),total bilirubin(TBIL),Scr,BUN,cystatin C(Cys-C),Child-Pugh grade C proportion,and model of end-stage liver disease(MELD)score in CHBCD+AKI group were significantly higher than those in CHBCD group(P＜0.05),and Alb was significantly lower in patients in CHBCD group(P＜0.05).In CHBCD+AKI group,hepatic encephalopathy,PT,TBIL,Cys-C,Child-Pugh classification,and MELD score were positively correlated with Scr and BUN(rs＞0,P＜0.05),and negatively correlated with Alb(rs＜0,P＜0.05).Scr ≥467.2pmol/L,BUN ≥ 11.5mmol/L,Cys-C≥2.7mg/L,Child-Pugh grade C,and MELD score≥ 15.4 points were independent signs of AKI secondary to the decompensated stage of CHB cirrhosis.BUN,Cys-C,and MELD scores were more effective than Scr and Child-Pugh grades in predicting AKI secondary to the decompensated stage of CHB cirrhosis.The median survival time of patients in CHBCD+AKI group was significantly lower than that of CHBCD group.Conclusion Scr,BUN,Cys-C,Child-Pugh grade,and MELD score are independent risk factors for AKI secondary to the decompensated stage of CHB cirrhosis,and the survival rate of AKI secondary to the decompensated stage of CHB cirrhosis reduced.