Abstract: Objective:To explore the relationship between angiotensin-converting enzyme 2(ACE2) gene 9570A/G polymorphism and the severity of coronary artery stenosis in the Han population of northern Anhui province. Methods:The ACE2 gene polymorphism in 120 CHD patients was detected by means of polymerase chain reaction and restriction fragment length polymorphism;the frequency of genotype and allele were compared according to the number of coronary artery lesions and the dangerous scores. Results:The number of coronary artery lesions and Genisini scores in the male patients with G genotype were higher than those with A genotype in CHD group(P0.05);however,there was no statistical difference in female patients with CHD(P0.05). Conclusions:The ACE2 gene 9570A/G polymorphism might be associated with the severity of coronary artery straitness of CHD in male patients in the Han nationality of northern Anhui province;however,female patients might have no such correlation.