Few studies have comprehensively evaluated how genetic modifiers of metabolic one-carbon stress as folate deficiency and hyperhomocysteinemia interact to modify the host-susceptibility of human heaptocellular carcinoma (HCC) development. Genetic polymorphisms of 3 key one-carbon enzymes (methylenetetrahydrofolate reductase: MTHFR, methionine synthase: MS, and thymidylate synthase: TS) at 5 loci were characterized in a case-control and hospital-based Asian population (n=398). The monopolymorphic analysis revealed that the T variant allele at MTHFR 677 loci in relative to the other genotyped variant alleles (MTHFR 1298C, MS 2756G, TSER 2R, TS3’UTR 1494+6bp insertion) was associated with a significant 40% reduction of HCC risks in the dominant model (adjusted ORs: 0.6, 95% CI: 0.4-0.9, P=0.03). Among individuals with low metabolic folate stress (serum folate>6 ng/mL), the MTHFR CC wild-type interacted with the TSER 2R variant alleles to increase HCC risks (OR: 0.14 vs. 0.3; 95% CI: 0.1-0.8), whereas 2-fold reduced HCC were associated with the compound MTHFR T and TSER 2R variant alleles (OR: 0.14 vs. 0.07; 95% CI: 0.02-0.2) (P for interaction: 0.044) after adjustment for serum homocysteine (Hcy) levels. The TSER 2R or TS3’UTR+6bp variant alleles interacted with MTHFR T variant allele to reverse its lowering serum folate and elevating Hcy effects (P for trend=0.009 and 0.001, respectively). Taken together, our data demonstrated that MTHFR 677 T and TSER 2R variant allele interacted to alleviate metabolic one-carbon folate stress, which folate-genetic interactions may be the important elements in favor of reduced HCC risks.