Abstract: Objective: To explore the significance of gene mutations of Methylenetetrahydrofolate reductase （MTHFR）, cystathionine beta-synthase （CBS） and methione synthase （MS） in elderly patients with peripheral arterial occlusive disease （PAOD）, and analyze the relation between them. Methods: The genotypes of MTHFR, CBS, MS were determined by PCR-based assay in 83 patients with PAOD （PAOD group） and 100 healthy controls （NC group） in elderly people. RESULTS: The frequencies of T/T genotype （homozygous mutant） of MTHFR were 19%; C/C （homozygous normal）, 31% in NC group and T/T, 34.9%; C/C 13.3% in POAD group respectively. The frequencies of allele T of MTHFR were 44% in NC group; 60.8% in POAD group respectively. The frequencies of homozygous T/T and allele T of MTHFR in POAD group were significantly higher than those in NC. There were no obvious differences in the frequencies of CBS, MS gene mutations between the PAOD and NC group. Conclusion: The C677T mutation in MTHFR gene is associated with the risk to peripheral arterial occlusive disease in elderly people of Beijing community.