Abstract： Objective： To observe the clinical effect of modified Zhenwu tang combined with routine western medicine therapy for Cardiorenal syndrome(CRS) of type Ⅰ with the heart- kidney yang deficiency and internal retention of water syndrome.Methods：A total of 80 cases of CRS patients of typeⅠwith the heart-kidney yang deficiency and internal retention of water syndrome were randomly divided into the control group and the observation group， 40 cases in each group. The control group was given routine western medicine therapy， such as diuretic， positive inotropic medicine， vasodilators， renin- angiotensin- aldosterone system blocker， as well as continuous renal replacement therapy(CRRT)， and the observation group was additionally given modified Zhenwu tang based on the treatment of the control group. Both groups were continuously treated for seven days. The clinical effect was compared between the two groups； the indexes of the heart function and the kidney function，the incidence of mechanical ventilation and mortality rate before and after treatment were compared between the two groups. Results：The total effective rate was 87.5% in the observation group，higher than that of 65.0% in the control group(P＜0.05). After treatment，the indexes of troponin(TnI)，B-type natriuretic peptide(BNP)， left ventricular end- diastolic diameter(LVEDD) and left ventricular end systolic diameter(LVESD) in the two groups were all decreased when compared with those before treatment， and the four indexes in the observation group were lower than those in the control group(P＜0.05). After treatment，the indexes of left ventricular ejection fraction(LVEF) in the two groups were increased when compared with those before treatment，and the index in the observation group was higher than that in the control group(P＜0.05). After treatment，the indexes of blood urea nitrogen(BUN)，serum creatinine(SCr) and cystatin-C (Cys- C) in the two groups were decreased when compared with those before treatment， and the three indexes in the observation group were lower than those in the control group(P＜0.05). After treatment，the urine volumes in 24 hours in the two groups were increased when compared with those before treatment， and the volume in the observation group was higher than that in the control group(P＜0.05). After treatment， there was no significant difference being found in the comparison of the incidence of mechanical ventilation and mortality rate between the two groups(P＞0.05). Conclusion：The therapy of modified Zhenwu tang combined with routine western medicine therapy in treating Cardiorenal syndrome of typeⅠ with the heart-kidney yang deficiency and internal retention of water syndrome，can significantly improve the heart and the kidney function of patients and reduce clinical symptoms，with reliable curative effect.