Objective To study the therapeutic effect of Yanshen Granule No.1 （Granule for Protecting Renal Function） on the residual renal function of maintenance hemodialysis patients and its possible mechanism. Methods The 64 patients with uremia due to chronic renal failure were randomized into treatment and control groups with 32 cases in each. Additionally

30 healthy people were enrolled in the healthy group for comparison. The control group was given routine hemodialysis

while the treatment group was administered Yanshen Granule No.1 for oral taking based on hemodialysis. Changes of residual renal function （RRF）

volume of urine

interleukin-1β （IL-1β）

interleukin -6 （IL-6）

tumor necrosis factor-α （TNF-α）

endothelin-1 （ET-1）

and angiotensin Ⅱ （AngⅡ） after treatment were observed for comparison with those of before treatment. Results In the treatment group

the decline of RRF and decrease of volume of urine were significantly slower than those of the control group （P<0.01）. The contents of IL-1β

IL-6

TNF-α

ET-1

and AngⅡ of treatment and control groups were increased significantly in comparing with those of healthy group. But the treatment group was better than the control group in decreasing various indices （P<0.01）. Conclusion Yanshen Granule No.1 has the protective function on the residual renal function of maintenance hemodialysis patients and its possible mechanism may be related to decrease of IL-1β

IL-6

TNF-α

ET-1

and AngⅡ.