Abstract: Objective：To compare the short- and long- term efficacies of the traditional diuretics combined with or without tolvaptan for the chronic decompensated heart failure patients with reduced left ventricular ejection fraction, and investigate the effect of tolvaptan on the prognosis of patients with chronic decompensated heart failure. Methods：A total of 115 patients with chronic decompensated heart failure were selected from the Department of Cardiology, Shanghai East Hospital and Tangzhen Community Health Center, Pudong New Area, Shanghai from February 2013 to May 2015. According to whether tolvaptan was additionally used, 115 patients were divided into standard treatment group (n=68) and tolvaptan group (n=47). The body weight of patients was recorded before and 1 week after the treatment, the plasma osmotic pressure was calculated, and the changing trend was analyzed by ANOVA for repeated measurement. All patients were followed up for 2 years, and Kaplan- Meier survival curve was plotted to analyze the incidence of heart failure readmission, non- fatal myocardial infarction, cardiovascular mortality, and all- cause mortality in the two groups. Cox multivariate regression analysis was used to analyze the prognostic factors. Results：The difference between the two groups in basic information was not statistically significant. After the treatment, the body weight and the level of N- terminal pro B- type natriuretic peptide (NT- proBNP) of patients in tolvaptan group were significantly lower than those in the standard treatment group (P<0.05). The average hospital stay and heart failure readmission in tolvaptan group were lower than those in the standard treatment group (P<0.01, 0.05). There was no significant difference in the incidence of non- fatal myocardial infarction, cardiovascular mortality, and all- cause mortality. Conclusions：On the basis of standard anti- heart failure drug therapy, tolvaptan can alleviate the clinical symptoms of patients with chronic decompensated heart failure, and reduce the average hospital stay and heart failure readmission rate. However, tolvaptan may not affect the incidence of non- fatal myocardial infarction, cardiovascular mortality, and all- cause mortality.