Objective: To investigate V264M polymorphism of tissue factor pathway inhibitor (TFPI) in patients with acute coronary syndrome(ACS) in Chinese. Methods: The genotypes of V264M were detected by polymerase chain reaction(PCR) and restriction fragment length polymorphism(PCR-RFLP) in 136 patients with ACS and 106 healthy controls with their plasmal f-TFPI tested by enzyme linked immunosorbent assay(ELISA). Results: Two genotypes were found in V264M: GG and GA. The distribution frequencies of alleles and genotypes were in accordance with those predicted by Hardy Weinberg equilibrium in the present study(?2 = 0.437, P > 0.05). Plasma f-TFPI level was lower in A allele bearer than that in non-A allele carriers and higher in ACS than control subjects (P < 0.05). No relationship was found between ACS and V264M polymorphism(P > 0.05). Conclusion: The V264M polymorphism may have an impact on the plasma level of free TFPI(f-TFPI), but it has no relationship with ACS. Methods: The genotypes of V264M were detected by polymerase chain reaction (PCR) and restriction fragment length polymorphism (PCR-RFLP ) in 136 patients with ACS and 106 healthy controls with their plasmal f-TFPI tested by enzyme linked immunosorbent assay (ELISA). Results: Two genotypes were found in V264M: GG and GA. The distribution frequencies of alleles and genotypes were in accordance with Those predicted by Hardy Weinberg equilibrium in the present study (? 2 = 0.437, P> 0.05). Plasma f-TFPI level was lower in A allele bearer than that in non-A allele carriers and higher in ACS than control subjects (P < 0.05). No relationship was found between ACS and V264M polymorphism (P> 0.05). Conclusion: The V264M polymorphism may have an impact on the plasma level of free TFPI (f-TFPI), but it has no relationship with ACS.