Abstract: To evaluate the effects of salvianolate, an aqueous extract of Salviae miltiorrhizae on the expression of Toll-Like Receptor 4 (TLR4) in microglia after Oxygen-Glucose Deprivation (OGD) followed by refusion using Real Time fluorescence quantitative PCR (RT-qPCR). The expression of TLR4 in primary cultured rat’s microglia was examined after OGD/Refusion injury, the interfering effect of salvianolate on TLR4 expression was investigated under the same condition. Experimental groups; control group 1: the rat<’s microglia cells were maintained in cell culture medium (DMEM/F12 supplemented with 10% heat-inactivated Fetal Bovine Serum (FBS) normal oxygen supply. Model group 2: cultured microglia cells were deprived of oxygen-glucose for 4 h and then refused for 12 h. Salvianolate group 3: microglia were incubated with salvianolate dissolved in glucose-free DMEM (10 mg L^-1) during OGD then maintained in the normal cell culture medium containing same concentration of salvianolate during refusion. The expressions of TLR4 in microglia cells in different experimental groups were tested by RT-qPCR. The expression level of TLR4 mRNA in model group was higher than that in control group also higher than that in salvianolate group with statistical significance (p<0.05) however there was no significant difference between the expression in control group and salvianolate group (p>0.05). OGD/Refusion injury activated the TLR4 signaling pathway in cultured microglia. The endogenous mediators might act as the ligands to up-regulate TLR4 and salvianolate significantly inhibited the activity. These results highlighted the importance of salvianolate as a potential therapeutic target in treating cerebral ischemia.