Aim To investigate the relationships between homocysteine (Hcy) and CHD, as well as the associations between Hcy related single nucleotide polymorphisms (SNP) and CHD in Han Population of Northeast Sichuan. Methods A case-control study design was adopted, the present study recruited 221 CHD patients and 210 age- and sex-matched healthy controls from Han Population of Northeast Sichuan. The levels of plasma Hcy were detected, 4 SNP on MTHFR C677T, MTHFR A1298C, MS A2756G, MTRR A66G genes were genotyped, associations between SNP, the levels of plasma Hcy and CHD were analyzed. Results (1)Plasma Hcy levels of CHD group (15.39±6.89 μmol/L) was obviously higher than that of control group(12.90±6.44 μmol/L), OR of Hcy was 1.060 (95%CI 1.021～1.100, P＜0.05).(2) There were no significant differences in genotype and allele frequencies of the MTHFR C677T, MTHFR A1298C, MS A2756G and MTRR A66G observed between groups. By MDR between MTHFR C677T, MTHFR A1298C, MS A2756G and MTRR A66G didn't have interaction, between MTHFR C677T and smoking, TG didn't have interaction. (3)The plasma Hcy levels of CHD patients with MTHFR C677T CC genotype was 13.99±4.77 μmol/L, the plasma Hcy levels of CHD patients with CT genotypes was 15.44±6.25 μmol/L, the plasma Hcy levels of patients with TT genotypes was 19.72±11.51 μmol/L, the difference of the plasma Hcy levels in CHD patients with TT genotypes and CC genotypes was statistically significant(P＜0.05). Conclusion Hcy may be a risk factor for CHD in Han Population of Northeast Sichuan.MTHFR C677T TT genotypes elevated the plasma Hcy levels in CHD patients, the gene polymorphism of MTHFR C677T, MTHFR A1298C, MS A2756G and MTRR A66G were not risk factors for CHD.