Objective:To study the protective effects of Shenmai injection (SMI,参麦注射液) on peritoneal mesothelial cell in rats with 5/6 nephrectomy. Methods:By using light microscopy and scanning electron microscopy the morpholgical structure changes of peritoneal mesothelial cell in rats with 5/6 nephrectomy caused (chronic)renal failure model of after the peritoneal didysis of SMI were observed at the same time the levels of C3 and IgG in peritoneal dialysate were observed also. Results:The SMI could promote the recovery and proliferation of injured peritoneal mesothelial cell increase the immunity function of abdomen in rats. Conclusions:The SMI has protective effect on peritoneal cell in rats with 5/6 nepherctomg the protecive effect related to improving regional defence function in abdomen.