目的　探讨大脑静脉窦血栓形成患者凝血因子ⅤLeiden突变的意义。方法　采用聚合酶链反应 (PCR)及限制性内切酶Mnl Ⅰ酶切的方法 ,鉴定 2 0例大脑静脉窦血栓形成患者及 5 0例对照者是否存在凝血因子ⅤLeiden突变。结果　所有受检者PCR产物经Mnl Ⅰ酶切后均产生 376 7和116bp 3个片段。结论　 2 0例脑静脉血栓形成患者与 5 0例对照者均无凝血因子ⅤLeiden突变 ,因此 ,凝血因子ⅤLeiden突变不是脑静脉血栓形成的主要危险因素 Objective To investigate the significance of coagulation factor ⅤLeiden mutation in patients with cerebral venous sinus thrombosis. Methods Polymerase chain reaction (PCR) and restriction endonuclease digestion with MnlI were used to identify the presence of coagulation factor ⅤLeiden mutation in 20 patients with cerebral venous sinus thrombosis and 50 controls. Results PCR products of all subjects were digested with MnI I to produce 376 7 and 116 bp 3 fragments. CONCLUSION: No coagulation factor Ⅴ Leiden mutation is found in 20 patients with cerebral venous thrombosis and 50 controls. Therefore, the mutation of Ⅴ Leiden factor is not the main risk factor of cerebral venous thrombosis