Objective:To investigate the effect and mechanism of Xiaoma Zhitong capsule on nerve conduction velocity in the treatment of diabetic peripheral neuropathy(DPN). Method: One hundred and two patients were randomly divided into control group(50 cases)and observation group(52 cases). The patients in control group received 500 mg methycobal and placebo 3 times daily

and the patients in observation group received 500 mg methycobal 3 times daily and Xiaoma Zhitong capsules 4 times daily. Patients in both groups received a 3 4-week periods of treatment. Curative effect

motor nerve conduction velocity(MNCV)and sensory nerve conduction velocity(SNCV)in two groups were observed

activity of aldose reductase(AR)

nitric oxide(NO)and superoxide dismutase(SOD)were compared between two groups. The curative effect was evaluated by toronto clinical scoring system(TCSS)and visual analogue score(VAS). Result: The total effective rate of control group was 90.4%

which was higher than control group(74.0%

P<0.05). MNCV and SNCV of patients in two groups were improved after treatment

and there was statistically significant difference in the observation group(P<0.05). Levels of AR were decreased(P<0.05)

NO and SOD were increased(P<0.05)in the observation group as compared with the control group(P<0.05). TCSS score in control group and treatment group were(6.27±1.17)

and(4.52±0.93)

respectively. VAS score in control group and treatment group was(5.33±0.64)and (4.26±0.53)

respectively. and the observation group had lower results(P<0.05). Conclusion: Using Xiaoma Zhitong capsule combined with methycobal had definite curative effect on diabetic peripheral neuropathy

it could obviously improve the peripheral neuropathy of diabetic patients. The effect may be related to regulating the activities of AR

NO and SOD.