Objective: To study therapeutic effect and mechanisms of inhalation of drug-oxygen Fuchong Xiangye for treatment of vascular dementia. Methods: 123 cases were randomly divided into treatment group and control group by single-blind. Thertapeutic effects

superoxide dismutase （SOD） activity in red cells

plasma lipid peroxide

triglyceride

serum cholesterol and high density lipid protein （HDL） levels

and electroencephalogram were investigated before and after treatment. Results: The improvement of symptom scores and the above indexes after treatment in the treatment group were more obvious than those in the control group

with no reserve reaction in both groups. Conclusion: Inhalation of drug-oxygen Fuchong Xiangye has a better therapeutic effect on vascular dementia

and the mechanism is related with decrease of blood lipid

and increase of HDL and SOD.