To explore the effect and mechanism of Guhong injection against cerebral ischemia reperfusion injury, SD rats were randomly divided into the sham-operated group, the model group, the nimodipine group, and high, medium and low-dose Guhong injection groups, with 10 rats in each group. The middle cerebral artery embolization (MCAO) model was established to observe neurological deficit symptoms, infarct volume, SOD activity, MDA content, GSH-Px and CAT activity in rats, as well as the contents of t-PA, PAI, TXB2 and 6-keto-PGF1α in serum. The results showed that Guhong injection could obviously promote the recovery of neurological deficit symptoms, narrow the brain infarct volume in rats after surgery, significantlyincrease the activities of SOD, GSH-Px and CAT and decrease the content of MDA. Meanwhile, it also could obviously increase the contents of t-PA and 6-keto-PGF1α and decrease the contents of PAI and TXB2 in serum, indicating that Guhong injection have better antioxidant and antithrombus effects, as well as a significant protective effect against cerebral ischemia reperfusion injury in rats.