Objective To evaluate the changes in cholinergic anti-inflammatory pathway in hippocampi global in aged rats with cerebral ischemia/reperfusion (I/R ) injury .Methods One hundred and twenty male Sprague-Dawley rats , aged 18-22 months ,weighing 450-600 g ,were randomly divided into 2 groups ( n= 60 each):sham operation group (group S) and global cerebral I/R group (group I/R) .The animals were anesthetized with intraperitoneal 10% chloral hydrate 0.4 ml/100 g .Global cerebral I/R was induced by 4-vessel occlusion method described by Pulsinelli .Fifteen rats were sacrificed at 1 ,3 ,5 and 7 days of reperfusion ,and brains were removed for determination of neuronal apoptosis and expression of α7 nicotinic acetylcholine receptor (α7nAChR ) , choline acetyltransferase (ChAT ) ,tumor necrosis factor-α(TNF-α) and interleukin-1β(IL-1β) in the hippocampal CA1 region .The apoptosis rate was calculated .Results Compared with group S ,the apoptosis rate was increased and the expression of α7nAChR ,ChAT ,TNF-αand IL-1βwas up-regulated in group I/R ( P〈0.05 or 0.01 ) . The expression of α7nAChR and ChAT was up-regulated gradually during reperfusion and peaked at 5 day of reperfusion ( P〈 0.05 ) .Conclusion Global cerebral I/R injury can activate cholinergic anti-inflammatory pathway in aged rat hippocampi ,and the activation of this pathway is the endogenous mechanism of inhibition of excessive inflammatory responses in brain tissues . Key words: Reperfusion injury; Brain; Cholinergic agonists; Aged; Hippocampus