Abstract: Objective:To observe the effects of soybean isoflavone on ATpases and the expressions of bcl-2 and bax after cerebral ischemia /reperfusion injury in rats and explore its protective mechanisms.Methods:Thirty male adult Sprague-Dawley rats were randomly divided into three groups:control group,ischemia /reperfusion injury (IR) groupand soybean isoflavone (SI) pretreatment group.The global ischemia /reperfusion injury model of rats was established by blocking three vessels,then reperfused for 1 h after 1 h ischemia.The brain tissues pathologic changes,the activities of Na+-K+-ATpase and Ca2+-Mg2+-ATpase as well as the expressions of bcl-2 and bax were observed.Results:Compared with IR group,the injury changes of SI groupwere obviously lessened,the activities of ATpases were incrased,and the expression of bcl-2 was promoted while bax was inhibited.Conclusions:Soybean isoflavone could relieve cerebral ischemia/reperfusion injury in rat model,and it was related to enhancing the activities of Na+-K+-ATpase and Ca2+-Mg2+-ATpase,increasing the expression of bcl-2 as well as inhibiting the expression of bax.