The aim of this study is to investigate the effects and mechanism of extract of Apocynum venetum (AV) on kidneys of streptozotocin-induced diabetic rats.  Diabetes mellitus (DM) was induced in rats by     intraperitoneal injection of streptozotocin (STZ).  The indexes of the blood glucose, renal function and     oxidative stress were observed.  The DM rats were administrated with the AV for 8 weeks, the above-mentioned indexes were detected.  The blood glucose level, BUN, 24 h urine protein excretion, urine volume, renal index, renal cortex’s MDA level in model groups all increased significantly.  Renal cortex’s SOD and GSH activities decreased significantly compared with the normal control group (P < 0.05).  The above-mentioned indexes were significantly improved by the AV treatment (P < 0.05).  AV have protective effects on renal function of kidneys of streptozotocin-induced diabetic rats, and maybe via inhibition of the renal oxidative stress.