OBJECTIVE： To investigate the correlation of gene polymorphism of MTHFR and MTRR with the occurrence of coronary heart disease in Han population in Shaanxi area. METHODS： Totally 350 Shaanxi Han patients with coronary heart disease were selected from cardiovascular department of the Second Affiliated Hospital of Air Force Medical University during Nov. 2016-May 2017 as case group. Totally 347 Shaanxi Han healthy volunteers were selected from the hospital in the same period as control group. The genotypes of MTHFR gene C677T， A1298C site and MTRR gene A66G site were detected by PCR assay. The genotype and allelic distribution were compared between 2 groups. The relationship between gene polymorphism and the occurrence of coronary heart disease was investigated. RESULTS： CC， CT and TT genotype in MTHFR gene C677T site， AA， AC and CC genotype in MTHFR gene A1298C site as well as AA， AG， GG genotype in MTRR gene A66G site were detected. In control group， the frequencies of CC， CT and TT genotype in C677T site were 26.80％， 44.96％， 28.24％； the frequencies of AA， AC and CC genotype in A1298C site were 71.18％， 24.78％， 4.04％； and the frequencies of AA， AG and GG genotype in A66G site were 54.47％， 38.62％， 6.91％， respectively. In case group， the frequencies of CC， CT and TT genotype in C677T site were 15.43％， 49.71％， 34.86％； the frequencies of AA， AC and CC genotype in A1298C site were 77.14％， 21.71％， 1.15％； and the frequencies of AA， AG and GG genotype in A66G site were 54.57％， 38.29％， 7.14％， respectively. The frequencies of genotype distribution in 2 groups were all in line with the Hardy-Weinberg equilibrium （P＞0.05）. There was statistical significance in genotype distribution frenquencies and allele frequencies in C677T and A1298C site between 2 groups （P＜0.05）. The frequencies of CC genotype distribution and C allele in C677T site， the frequencies of CC genotype distribution and C allele in A1298C site in control group were significantly higher than case group， with statistical significance （P＜0.05）. There was no statistical significance in genotype distribution frequencies or allele frequencies in A66G site between 2 groups （P＞0.05）. CONCLUSIONS： MTHFR gene is mainly mutant type in C677T site and wild type in A1298C site among Han population in Shaanxi area. Gene polymorphism of above two sites may be associated with the occurrence of coronary heart disease； C677T site mutation may be a risk factor for coronary heart disease， while A1298C site mutation may be a beneficial factor. MTRR gene polymorphism in A66G site maybe has no relationship with coronary heart disease in the population.