【Abstract】 Objective To explore the relationship between CYP2C9 and VKORC1 gene polymorphisms and warfarin maintenance dose in northeastern Sichuan Han patients. Methods CYP2C9 and VKORC1 genotypes were detected by using fluorescent in situ hybridizationstaining sequencing detection system from 100 unrelated Han patients in northeastern Sichuan Province, and 100 patients taking warfarin were followed up to assess the effect of CYP2C9 and VKORC1 on warfarin dosage. Results Among 100 patients who received maintenance dose at warfarin, there is 890% of AA type, 110% of AC type and 0% of CC type in CYP2C9 1075 gene; 20% of GG type, 860% of AA type and 120% of GA type in VKORC1 1639 gene. The amount of warfarin in different genotypes is as follows: 305 ± 087 mg/d of AA type , 213 ± 054 mg/d of AC type in CYP2C9 1075 gene; 490 ± 122 mg/d of GG + GA type, 258 ± 065 mg/d of AA type in VKORC1 1639 gene. The maintenance dose of warfarin with different genotypes was respectively compared to P＜ 005, both of them were statistically significant. Conclusion CYP2C9 and VKORC1 gene polymorphisms may affect the dose of warfarin in patients of Han nationality in northeastern Sichuan. The results of CYP2C9 and VKORC1 gene polymorphisms may provide evidence for adjusting the dose of warfarin in clinical treatment．