Objective: The purpose of this research is to explore the effects that Shuanggen Qingnao Granules towards vascular dementia(VD) by observing animal behavior and superoxide dismutase

malondialdehyde

nitric oxide and nitric oxide synthase levels in serum of VD rat model. Method: Vascular dementia (VD) rat models was made by injecting the same kinds of thrombotic emboli to the catheter of the external carotid artery. Morris water maze test is used for measuring the learning and memory ability. The photochemical reaction for contents of SOD in serum and MDA as well as NOS activity and nitratase method for NO levels were used. Result: The time for the rats taken Shuanggen Qingnao Granules to escape the latent period and to cross the platform for the first time was significantly shortened(P<0.05

P<0.01). SOD activity increased in medium and low-dose rehabilitation groups. And the MDA content decreased. The ratio of SOD and MDA(SOD/MDA) in the treated groups has all elevated(P＜0.01).Besides

the NO contents in the treated groups decreased (P<0.05

P<0.01). And the NOS activity in the medium and low-dose groups increased(P＜0.01). Conclusion : Shuanggen Qingnao Granules can significantly improve the learning and memory ability of the rats with VD. It can also increase SOD activity. Meanwhile

it decreases MDA and NO contents as well as NOS activity.