D-二聚体是交联纤维蛋白降解后的一种特异性产物。其水平增高提示体内凝血酶的生成及继发性纤溶系统的激活，是血栓前状态的一个敏感指标，与临床中的血栓性疾病密切相关。特别是针对肺栓塞，作为一个早期的筛查指标，具有高度的敏感性，减少了肺栓塞的误诊及漏诊。近年来，临床中发现在主动脉夹层、恶性肿瘤、急性脑梗死、心房颤动等疾病中 D-二聚体水平亦有升高。对于此类疾病的早期诊断、评估治疗效果及其预后具有重要意义。“,”D-Dimer is a specific degradation product of cross-linked fibrin and its increased level in plasma is a biomarker indicating activation of coagulation and fibrinolysis ,therefore it is a sensitive index of venous thromboembolism,especially in the pulmonary embolism ( PE) for its early screening with high sensi-tivity,which reduces the misdiagnosis,and missed diagnosis of PE.Recently,it′s discovered that D-dimer level also increases in acute aortic dissection,cancer,acute stroke,atrial fibrillation,therefore it′s also of great significance for the early diagnosis,treatment effect assessment and prognosis of these diseases.