Objective To evaluate the efficacy of butylphthalide in treatment of diabetic peripheral neuropathy (DPN). Methods 85 patients of diabetic peripheral neuropathy were randomly divided into 43 patients with butylphthalide treatment group and 42 as controls. The treatment group was administrated with butylphthalide (200 mg tid po) , mecobalamin (0. 5 mg tid po) , thiamine tetrahydrofurfuryl disulfide (25 mg tid po) and vitamin B6 (20 mg tid po) , for 3 weeks. The control group was only given vitamins. Before and after treatment, the efficient rate and nerve conduction velocity were compared between two groups. Results After treatment, the neurological symptoms and signs were significantly improved in two groups, totally the effective rate (81. 4%) in the treatment group was significantly higher than that in the control group (59. 5%,P0. 05). Except for the median nerve of the control group, sensory and motor conduction velocity increased obviously after treatment in both the treatment group and the control group ( P 0. 05 , P 0. 01). After treatment, sensory and motor conduction velocity in the treatment group was higher than the index in the control group (P0. 05). Conclusions Butylphthalide combined vitamin B has a reliable efficacy on treatment of diabetic peripheral neuropathy.