Objective:To observe the therapeutic effect of α lipoic acid combined with mecobalamin on diabetic peripheral neuropathy(DPN).Methods:80 patients with diabetic peripheral neuropathy were randomly divided into the combination treatment group(treatment group,40 cases) and single-drug group(control group,40 cases).The treatment group were treated by α lipoic acid and mecobalamin,the control group were treated by mecobalamin.The treatment courses were 4 weeks for both groups.They were observed the therapeutic effect and nerve conduction velocity(NCV) for the two groups at the end of treatment.Results:The total efficacious rate of treatment group reaches 92.5%,was higher than the control group 62.5%(P<0.05);After the treatment for 4 weeks,the treatment group's nerve conduction velocity was significantly improved(P<0.05) than the control group.Conclusions:α lipoic acid combined with mecobalamin is effective in treating diabetic peripheral neuropathy,can effectively improve nerve conduction velocity of the DPN patients.