Objective:To study the effect of Naomaitai capsule on cognitive dysfunction of vascular dementia patients.Method: Eighty four vascular dementia patients were randomly divided into therapeutic group and control group（n=41 each）.The therapeutic group was treated by Naomaitai capsule（2 capsules

tid） and the control group by Naofukang（2 tablets

tid）.The therapeutic course was 12 weeks.Before and after treatment

mimi-mental state examination（MMSE） grade and variation of frenquently appeared potential（P300） were evaluated.Clinical efficacy was evaluated for the two groups.Result: After the therapeutic course

the total efficacy of the observation group was better than that of the control group

the difference was statistically significant（p<0.05）.In two groups MMSE scores

P300 latency and P300 amplitude was significantly improved after treatment compared with those before treatment（P<0.05 or P<0.01）.The improvement in the treatment group was better than that in the controls.Conclusion: Naomaitai capsule for treating vascular dementia shows good efficacy and less adverse reactions.The capsule can promote cognitive recovery.