Objective To investigate the relationship between matrix metalloproteinase-9 (MMP-9) gene-1562 C/T polymorphism and hemorrhagic transformation (HT) from (IS) in Chinese Han population in Henan province.Methods The promoter-1562 C/T gene polymorphism in 84 IS patients with HT and 138 age-and sex-matched IS patients without HT were tested by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).The genotypes and alleles frequencies of-1562 C/T polymorphism were analyzed.Results The frequency of CT and TT genotype and T allele was lower in IS patients with HT than in IS patients without HT (17.86％ (15cases) vs.30.43％ (42 cases),8.93％ (15 cases) vs.15.94％ (44 cases),x2=4.326 and 4.458,P=0.037 and 0.035).The relative risk for HT from IS was decreased in patients with T allele than those withCTandTTgenotype[0.517 (95％CI:0.278-0.961) vs.0.497 (95％CI:0.255-0.967)].Conclusions The MMP-9 gene-1562C/T polymorphism may be related to hemorrhagic transformation of in Chinese Han population in Henan province.The T allele is a protective factor for hemorrhagic transformation of in the population.