AIM: To research the effect of erythropoietin (EPO) to the HIF-1\iNOS signal transduction path in retina in chronic ocular hypertension rat. METHODS: One hundred and twenty Wistar rats were divided into 12 groups randomly. Two episcleral veins were coagulated unilaterally in rats with electric coagulator to establish the glaucoma model. PT-PCR and Western Blot analysis were used to examine the expression of Caspase-9 genes in retina. And the changes of ERG-b wave before and after were detected using EPO. RESULTS: In EPO drug treatment group, the amplitude of ERG-b wave of retina restored remarkably. There was significant difference between two groups (P＜0.05). The expressions of HIF-1\iNOS mRNA and protein in EPO drug treatment group were weakened remarkably. It was statistically different compared with the non-drug treatment group. CONCLUSION: One of protect mechanisms of EPO to injured retina caused by chronic intraocular hypertension is through HIF-1\iNOS signal conduct path.