AimTo observe the expression of interleukin-10 (IL-10) on cerebral vascular endothelial cells in smoking rats, and to discuss the mechanism of ischemia in brain caused by smoking.Methods 60 health Wistar rats were divied into 6 groups: normal control group, sham exposure group, exposed cigarette smoke 30 days group, exposed cigarette smoke 30 days then stopping exposion for 30 days group, exposed cigarette smoke 90 days high dose group and exposed cigarette smoke 90 days low dose group. The expression of IL-10 were observed in smoking rats by immunohistochemistry stain.Results The expression of IL-10 in normal control group and sham exposure group were more. The expression of IL-10 in exposed cigarette smoke 90 days high dose group were significantly lower than those in the other passive smoking groups. The expression of IL-10 in exposed cigarette smoke 30 days then stopping exposure for 30 days group were significantly higher than those in the other passive smoking groups. The expression of IL-10 in the passive smoking groups were significantly lower than those in control group and the sham exposure group (p<0.05).ConclusionsSmoking can decrease IL-10 expression in endothelial cell, which plays an important role in ischemic cerebral vascular disease.