Objective:To explore the predictive value of thrombus markers for venous thromboembolism (VTE) in patients with malignant tumors after surgery.Methods:The clinical data of 150 patients with malignant tumors after surgery admitted to Cangzhou Hospital of Integrated Traditional Chinese Medicine and Western Medicine in Hebei Province from July 2020 to February 2021 were retrospectively analyzed. All 150 patients followed-up for 4 weeks were treated as the observation group, including 30 cases with VTE (the thrombosis group) and 120 cases without VTE (the non-thrombosis group). Another 60 cases undergoing healthy physical examination during the same period were selected as the control group. The chemiluminescence immunoassay was used to detect thrombin-antithrombin complex (TAT), plasmin-α 2 plasmin inhibitor complex (PIC), thrombomodulin (TM), tissue-type plasminogen activator inhibitor-1 complex(tPAIC). The control group was tested once, and the observation group was tested on the 1 day before the operation and 1 day after the operation. Receiver operating characteristic (ROC) curve was used to evaluate the predictive value of thrombus markers for VTE in patients with malignant tumors after surgery. Results:The patients with lung cancer ( χ2 = 12.53, P = 0.014), ≥ 60 years old ( χ2 = 6.66, P = 0.036),body mass index>30 kg/m 2 ( χ2 = 40.53, P<0.001), tumor metastasis ( χ2 = 5.38, P = 0.031), Ⅲ-Ⅳ stage ( χ2 = 5.83, P = 0.023) had higher incidence of VTE after the operation, and the difference was statistically significant. The levels of TAT, PIC and TM in the observation group were higher than those in the control group (all P < 0.05).The levels of TAT and TM in the thrombosis group were higher than those in the non-thrombosis group before the operation, and the difference was statistically significant (all P < 0.05).The value of TM in predicting VTE was high [the best cut-off value was 10.70 TU/ml, area under the curve (AUC) was 0.786, the sensitivity was 73.30%, the specificity was 81.70%], the combination of TAT and TM could improve the predictive value (AUC was 0.796, the sensitivity was 80.00%, the specificity was 77.50%). The levels of TAT, PIC, TM and tPAIC in thrombosis group were all higher than those in the non-thrombosis group after the operation, and the difference was statistically significant (all P < 0.05). The value of TAT in predicting VTE was high (the best cut-off value was 16.50 ng/ml, AUC was 0.887, the sensitivity was 82.36%, the specificity was 71.65%), the combination of TAT, PIC, TM and tPAIC could improve the predictive value (AUC was 0.913, the sensitivity was 90.00%, the specificity was 88.60%). The level of PIC was positively correlated with TAT before and after the operation ( r = 0.66, P < 0.001; r = 0.64, P < 0.001). Conclusions:TM can be used as a sensitive indicator in the early prediction of VTE for the patients with malignant tumors and it aims at the prevention; TAT can be used as a specific indicator in predicting the development of VTE and it aims at the intervention in time. The combined detection of TAT, PIC, TM and tPAIC can improve the predictive value of VTE. At the same time, PIC can be used to evaluate the risk of bleeding.