Abstract: Objective: To investigate the expression of Apelin in kidney tissues of adriamycin-induced nephrotic rats and the relationship between Apelin and urine protein excretions,serum cholesterin in the development of nephrosis. Methods: Forty Wistar rats were divided into nephrosis group and control group. Rat model of Nephrosis was induced by single intravenous injection of adriamycin (ADR) 5 mg/kg,while control rat was intravenously injected with normal saline. The levels of urine protein excretions and serum cholesterin in 24 h were measured by chemical chromatometry. The changes of apelin expression in kidney were detected by method of HE,and its correlations to urine protein and serum cholesterin were analyzed. Results: Compared with control group,the levels of 24 h urine protein excretions and serum cholesterin were significantly increased in nephrosis group (P < 0.05-P < 0.01). There was positive correlation between the expression of apelin protein in kidney tissues and the level of urine protein excretions or serum cholesterin(P < 0.05). Conclusions: The Apelin expression is located in glomerular capillary loops. There is the levels of expression of urine protein excretions and serum cholesterin are closely related with the apelin expression in kidney is correlated with proteinura and hyperlipidemia in the development of nephrosis.