Blood of 109 eases with cerebrovascular diseases were investigated. The results indicated that the contents of blood SOD, GSH-PX were remarkably decreased, while those of plasma LPO were increased. Compared with healthy individuals there was significant difference m these figures (P0.05). The SOD/LPO rate was lower than control group. The authors considered that the balance between anti-oxidase and LPO was disturbed in patients with cerebrovascular diseases.