Aim To evaluate the association between the molecular variants of rennin angiotensin system and the risk of acute myocardial infarction(AMI) in Chinese Han population. Methods Insert/deletion(I/D) of angiotensin converting enzyme(ACE) and angiotensinogen(AGT) T174M polymorphisms were determined by the means of polymerase chain reaction(PCR) in 112 AMI patients and 128 patients without AMI. Results The frequencies of DD genotype and D allele in patients with AMI were higher than those without AMI(p<0.01).The frequencies of MM genotype and M allele in patients with AMI were higher than those without AMI(p<0.05).In combined genotype analysis,the genotype of ACE DD+AGT 174MM was significantly higher in patients with AMI than those without AMI(p<0.01).The odds ratio estimated by the combined analysis of the ACE DD and AGT 174MM genotypes(OR=8.467) was markedly increased compared with that estimated separately from the ACE DD(OR=2.558) or AGT 174MM(OR=6.176) genotype. Conclusion The study suggests that AGT 174M allele and ACE D allele should be a risk factor for AMI in Chinese Han population and combined analysis of the ACE DD and AGT 174MM genotype may enhance the predictability of AMI.