Objective To observe the clinical efficacy of low-dose dobutamine combined with tolvaptan in the treatment of type Ⅰcardiorenal syndrome.Methods A total of 104 patients with type 1 cardiorenal syndrome admitted to the Department of Cardiology,Xinhua Hospital Affiliated to Shanghai Jiao Tong University of Medicine were selected as study subjects.The patients were randomly divid-ed into control group and experimental group,52 patients in each group.The control group which accepted oral tolvaptan 15mg,and the experimental group which accepted the treatment of low-dose of dopamine[2μg/(kg·min)]with intravenous infusion,and they were treatment for 7d.The primary endpoint was the cardiorenal serological index after 7days of treatment.Results After treatment,the total effective rates of experimental group and control group were 86.53％(45/52)and 67.30％(35/52),respectively,and the difference was statistically significant(P＜0.05).After treatment,the serological levels of cardiorenal functions and 12h urine volume were more significantly improved in two groups,and the improvement effect of experimental group was better than that of control group,the difference was statistically significant(P＜0.05).The levels of serum inflammatory cytokines after treatment were significantly lower than before treatment,and the difference was statistically significant(P＜0.05).Conclusion Low-dose dopamine combined with tolvaptan in treating type 1 cardio-renal syndrome can significantly improve patients'cardiac and renal function.