Objective: the rennin-angiotensin system plays an important role in the regulation of blood pressure as well as water and sodium balance and in the pathogenesis of cardiovascular disorders including left ventricular hypertrophy(LVH), The aim of the study was tio determine whether a positive correlation exists between the polymorphisms of angiotensin-converting enzyme(ACE) insertion/deletion(I/D) gene, angiotension II type I receptor(AT1R) A1166C gene, and angiotensinogen(ATG) T174M gene and LVH in Korean hypertensives. Design and Methods : We studied 135 hypertensives patients. ACE gene I/D polymorphism, angiotensin type I receptor gene A1166C polymorphism, and ATG gene T174M polymorphism were analyzed by molymerase chain reaction(PCR) and sequencing analysis. The left ventricular mass index(LVMI) was calculated by M-mode of 2-dimensional echocardiography. With cut-off level of 125g/m2, subjects were classified into LVH and non-LVH groups. The association between polymorphism of ACE gene, AT1R gene, and ATG gene and echocardigraphic LV mass was analyzed using analysis of variance and chisquare testing. Results: Baseline characteristics of LVH and non-LVH groups were similar except total cholesterol level. When we compaired the genotypes and allele frequency of ACE gene, AT1R gene, and ATG gene, there were no difference between LVH and non-LVH groups. Conclusions: I/D polymorphism of the ACE gene, A1166C polymorphism of AT1R gene, and T174M polymorphism of ATG gene did not influence left ventricular hypertrophy in Korean hypertensives