Aim To investigate the association between myocardial infaction(MI) and functional matrix metalloproteinase-9 polymorphism(C1562T). Methods A case-control study of seventy-eight patients with angiographically documented MI and eighty-one control subjects with a normal angiogram was conducted.Genotype was determined by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) for the common C1562T functional promoter polymorphism of the MMP-9 gene. Results The results of individual polymorphisms analysis showed that the frequency of C/T genotype and 1562T allele of MMP-9 gene of MI patients(26.9% and 13.5%) were significantly higher than that in control group(9.9% and 4.9%;p<0.01). Conclusion The present findings suggest that the genetic polymorphism in MMP-9 promoter(C1562T) is associated with the susceptibility to MI in the Han population of China.