Aim To explore the association between coronary heart disease (CHD) and gene polymorphism of three key genes in renin-angiotensin system, including insertion/deletion (I/D) polymorphism of angiotensin converting enzyme (ACE) gene, M235T polymorphism of angiotensiongen (AGT) gene and A1166/C polymorphism of angiotensin Ⅱ type 1 receptor(AT1R) gene. Methods Single gene and gene linkage were respectively analyzed by polymerase chain reaction combined with restriction fragment length polymorphism (PCR-RFLP) in 110 patients with CHD and 80 healthy subjects. Results ① The frequency of DD genetype (43.6%) and D allele (60.5%) in CHD group were markedly higher than that in nomal control group (26.3% and 44.4% respectively, P<0.05). The frequency of TT genetype (66.4%) and T allele(78.6%) in CHD group were significantly higher than that in nomal control group (42.5% and 60.6% respectively, P<0.05). Both the genotype frequencies of AA and AC and the allele frequencies of A and C did not differ in CHD group and in nomal control group (P>0.05). ②The odds ratio (OR) estimated by combined analysis of those three genotypes was higher than either ACE-DD(3.395 vs 2.175) or AGT-TT (2.669) genotype estimated alone. Yet, OR decreased compared with ACE-DD and AGT-TT genotypes (6.098) estimated by combined analysis. Conclusions There is a strong correlation between CHD and I/D polymorphism of ACE gene and M235T polymorphism of AGT gene. No significant association between A1166/C polymorphism of AT1R gene and CHD is confirmed in this study. And combined analysis of the ACE-DD and AGT-TT genotype may enhance the predictability of CHD.