Objective Objective TO investigate the potential association between matrix metalloproteinase-9 (MMP-9) gene polymorphisms and risk of ischemic stroke in Western Guangdong population.Methods This hospitalbased case-control study recruited 251 patients with ischemic stroke and 96 controls.Using Multiplex SNaPshot method was used to detect the genotype of MMP-9 gene rs3787268、rs3918241 and rs3918242 polymorphisms.The association between MMP-9 gene polymorphisms and risk of ischemic stroke was analyzed.Results ① There were significant differences in the genotype distribution of rs3787268 between ischemic stroke group and the controls (P=0.042).In the recessive model,the individual risk of A/A genotype was higher (OR=2.21,P=0.046) than that of the G/G+G/A genotype.② Compared with the controls,the genotype and allele distribution of rs3918242 in the ischemic stroke group were significantly different (P=0.007,P=0.038).In the dominant model,the risk of individuals carrying the T genotype was significantly elevated (OR=2.14,P=0.009) compared with individuals with the C/C genotype.③ The genotype distribution of rs3787268 polymorphisms in the LAA but not in no-LAA subgroup was significantly different from that in the controls (P =0.039).The genotype distribution and allele frequency of rs3918242 polymorphisms in the LAA subgroup were significantly different from that of the control group (P=0.009,P=0.047).There was no significant difference in the genotype distribution and allele frequency between no-LAA subtype and the control group.Conclusions The MMP-9 gene rs3918242 and rs3787268 polymorphisms may be the risk factors of ischemic stroke in Han population in the western part of Guangdong province,China.The MMP-9 gene rs3918242 and rs3787268 polymorphisms may be the risk factors of large-artery atherosclerotic stroke.