Abstract: Venous thromboembolism (VTE) has a close relationship with malignant tumors. VTE can not only increasethe difficulty of treatment for patients, but also decrease the quality of life and survival expectation. Thereforedoctors pay more and more attention to the problem, which has recently become a focus of oncological research.Tumor cells can produce cancer procoagulants and release cytokines by activating mononuclear cells andmacrophages. These proteins can induce blood coagulation and increase the risk of VTE. A certain special typesof tumor, such as primary brain tumor, pancreatic cancer, ovarian cancer, breast cancer, colorectal cancer andnon-small cell lung cancer, have a high risk of VTE. In addition, venous stasis, antitumor drug therapy and pro-gesterone are also risk factors of VTE. A comprehensive medical history combined with physical examination andbasic laboratory testing can detect a large proportion of occult malignancies in patients with idiopathic VTE.Whether advanced examinations could promote survival expectation in these patients depends on future clinicalresearch. The prophylaxis strategy using unfragnated heparin, low molecular weight heparin and pentosan beforemajor surgery can reduce the risk of postoperative VTE and the effect of these three anticoagulants are similar.The extended prophylaxis with LMWH for discharged cancer patients can also reduce the risk of VTE. But low-doseanticoagulant therapy does not reduce the risk of symptomatic CRT. The essentiality and efficacy of anticoagulantprophylaxis in medical cancer patients have not been well recoganized. Further clinical research is needed for theidentification of perfect strategy to prevent VTE in cancer patient.