Objective To observe the therapeutic effect and neural protection mechanism of Jiawei Bugan Decoction（Modified decoction for reinforcing the liver）on the diabetic peripheral neuropathy（DPN）.Methods Eighty DPN patients were randomized into treatment group and control group with 40 in each.Forty healthy subjects were selected as normal control.The two intervention groups received basic treatment

the treatment group was additionally administered Jiawei Bugan Decoction

while the control group injected vitamin B1 and vitamin B12 intramuscularly.The treatment lasted 8 weeks in both groups.Before and after treatment

the levels of serum vascular endothelial growth factor（VEGF）and insulin-like growth factor 1（IGF-1）of the patients were detected

simultaneously the electromyographic nerve conduction velocity（NCV）was measured for observing the clinical efficacy.Results The total effective rate of the treatment group was 82.5%

significantly higher than that of the control group（57.5%

P<0.05）.After treatment

NCV of both groups was significantly higher than before treatment（P<0.05）

compared with the control group

the NCV increase in the treatment group was more significant（P<0.05）.The level of IGF-1 was increased and the level of VEGF decreased in both groups than before treatment（P<0.05）

compared with the control group after treatment

the IGF-1 increase and VEGF decrease in the treatment group were more significant（P< 0.05）.Conclusion Jiawei Bugan Decoction functions to improve effectively the clinical symptoms and increase the IGF-1 level and decrease the VEGF level of the DPN patients.This may be one of its mechanisms in treating DPN.