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 (χ2 = 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.