Abstract: Objective To explore the preventive treatment of rosiglitazone ondelayed cerebral vasospasm (DCVS) after subarachnoid hemorrhage (SAH) in rats and its relationship with TLR4/NF-κB signaling pathways. Methods Forty-five adult healthy male SD rats were randomlydivided into SAH model group (n=15), control group (n=15) and rosiglitazone group (n=15). For rosiglitazone group, autologous blood was injected into the rats' cisterna magna to establish SAH animal model, rosiglitazone (3 mg/kg, with solvent of 10%dimethyl sulfoxide, 0.5 mg/ml) was intraperitoneally injected at 1 hour before and after the first and second bloodinjection. For control group, the equal volume of 0.9% sodium chloride injection was injected and the equal volume ofdimethyl sulfoxide was injected intraperitoneally. For SAH group, the equal volume ofdimethyl sulfoxide was injected intraperitoneally after the establishment of SAH model. Sevendays after injection, the basilar artery spasm was observed with HE staining and the basilar arterydiameter, arterial wall thickness were examined. Western blot was used to examine basilar artery's expression of TLR4 and IL-6. Results Thediameter of basilar artery were significantly smaller in SAH group and the thickness of arterial wall in SAH group significantly increased when compared with normal group (P< 0.01). Compared with SAH group, the basilar arterydiameter in rosiglitazone group increased and the thickness of arterial walldecreased (P< 0.01). Western blot showed that when compared with SAH group, expression of TLR4 and IL-6decreased significantly in rosiglitazone group (P< 0.01). Conclusion Rosiglitazone can inhibit TLR4/NF-κB signaling pathways, thus alleviatingdCVS after SAH and reducing the expression of TLR4, IL-6 in basilar artery.