To study the effect of Panax notoginseng saponins(PNS)on the expression of RIG-I in mimic ischemic cerebral microvascular endothelial cells(BMECs).Methods:Rat BMECs were cultured in oxygen-glucose-deprived(OGD) conditions to mimic cerebral ischemia in vitro.Firstly，the optimal concentration of PNS was determined by various concentration?gradients of PNS being administrated on OGD-induced BMECs.Then,the expression levels of RIG-I mRNA and protein in each group cells were detected by Q-PCR and Western blot method.Results:PNS can significantly improve the cells activity at 22μg/mL concentration，and decrease the expression of RIG-I in gene and protein levels in the OGD-induced BMECs.Conclusion:PNS has a protective effect on mimic ischemic BMECs，the mechanism may be related to the down-regulation of RIG-I expression，which may be one of the mechanisms of anti-inflammatory effects of PNS in cerebral ischemic injury.