Aim To study the association between insertion /deletion (I/D) polymorphism of angiotensin converting enzyme gene and coronary heart disease (CHD) in Hunan Han population. Methods By polymerase chain reaction (PCR), 100 patients with CHD and 54 healthy people were detected for their angiotensin-converting enzyme (ACE) genotypes and allele frequencies. Angiotensin Ⅱ (Ang Ⅱ), nitric oxide (NO) and endothelins (ET) were also detected in the above people. Results The frequencies of DD genotype and allele of CHD group were marked higher than that in control group (p<0.01), the odds rate (OR) of DD genotype compared with ID+II genotype was 7.27 (χ 2=13.42, 95%CI: 2.38～22.24). The levels of Ang Ⅱ and ET/NO in CHD group are significantly higher than that in control group (p<0.05 or 0.01). Conclusion There might be close relationship between DD genotype of ACE gene and CHD in Hunan Han population.