Objective To observe the therapeutic effect of recombinant human nerve growth factor (rhNGF) on diabetic peripheral neuropathy (DPN) rats.Methods Healthy adult male SD rats were induced to diabetes rats by i.m. injection of streptozotocin.After a month, rats with the tail sensory nerve conduction velocity (SNCV) <30 m/s were confirmed as DPN model rats.DPN rats were randomly divided into six groups, including the model control group, the investigational drug rhNGF I, II, III, IV (doses of 0.3, 1, 3, 9μg/kg) 4 dose groups and the pos. control group (epalrestat 15 mg/kg), concomitantly with the normal control group.During the administration of 2 mo, body weight of rats were detected weekly, blood glucose and SNCV monthly, sciatic nerve conduction velocity (MNCV) was detected after the last administration, and levels of sorbitol and fructose in sciatic nerve were last measured.Results Body weight, blood glucose, SNCV and MNCV of the model control group were significantly different with the normal control group after a month (P<0.01), showed that the successful modeling of DPN.The investigated drug rhNGF and the pos. drug epalrestat had no significant effect on body weight and blood glucose of DPN rats (P>0.05), but improved SNCV and MNCV.At 2 mo, SNCV in rhNGF group (III) and MNCV in rhNGF group (II, III) were significantly higher than the model control group (P<0.05).Levels of fructose and sorbitol in sciatic nerve raised in DPN rats, indicated the relationship between DPN and polyol metabolism rhNGF reduced fructose and sorbitol in sciatic nerve, with dose effect in fructose but not in sorbitol.Conclusion rhNGF has a significant protective effect on nerve of DPN rats, which may be associated with improvement of polyol metabolism similar with epalrestat.