Abstract: Objective To investigate whether ATP-binding cassette transporter 1(ABCA1) 69C/T single nucleotide polymorphisms variation is correlated with coronary heart disease(CHD) in the Inner Mongolia region，and the association of this polymorphism with blood lipids，degree of pathological changes in coronary artery . Methods The target fragments of ABCA1gene was amplified and analyzed by polymerase chain reaction(PCR)-restriction fragments length polymorphism(RFLP) technique in 345 patients with CHD and control subjects without CHD. Results 1. The frequency of TT genotype and T allele of ABCA1 69C/T gene was all significantly higher in CHD patients than that in controls(P<0.05). TT genotype odds ratio was 2.938（95%CI: 2.048～4.216，P <0.05）．It was shown TT genotype were risk factors for CHD accidents by logistic analysis. 2. There was an obviously different distribution frequency of the TT genotype and T alleles of 69C/T gene in single、double and multi coronary artery lesion group(P<0.05)，as well as that in A、B and C type group of coronary artery lesion(P<0.05). Conclusions ABCAl gene 69C/T polymorphism is associated with CHD risk in the Inner Mongolia region．The TT genotype and T alleles of the ABCA1 gene 69C/T polymorphism is associated with increased CHD risk. The TT genotype and T alleles of the ABCA1 gene 69C/T、-565C/T can increased the area and severity of coronary artery lesion.

Key words: coronary heart disease, ATP binding cassette transporter 1, coronary artery lesion