Objective To observe the effect of Astragalus Injection(AI) on aquaporin-1(AQP-1) expression of peritoneal mesothelial cells in rats with peritoneal dialysis.Methods Twenty-five male SD rats were divided into the normal control group(N =7),model group(N =9) and AI group(N =9).Except the normal control group,the model group was given intraperitoneal injection of peritoneal dialysate(containing glucose 42.5 g/L),and AI group was given intraperitoneal injection of peritoneal dialysate(containing glucose 42.5 g/L) plus AI(20 mg/mL),25mL/d for 10 continuous days.On the 11th day of experiment,the amount of dialysis ultrafiltration(UF) and net UF,and the concentration ratio of dialysate and plasma sodium(D/PNa) were measured,peritoneal pathological changes were observed with light microscope,and the expression of AQP-1 in peritoneal mesothelial cells was detected with immunohistochemical method.Results When the peritoneal dialysate was kept in the abdominal cavity for 60 min,the amount of UF and Net UF was increased in AI group(P