Objective: To observe the expression alterations of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in the endothelial cells of rabbits with thrombosis of posterior vena cava (PVC) and the effects exerted by thrombolytic and anticoagulant therapy. Methods: Sixty healthy adult New Zealand white rabbits were equally randomized into model group and treatment group after the establishment of PVC thrombosis model with the coarctation procedure. After the confirmation of model establishment by contrast examination on the second postoperative day, rabbits in treatment group received thrombolytic and anticoagulant therapy while those in model group were given normal saline of the same volume. At the 1, 4 and 7 d after dosing administration, 10 rabbits at each time point were randomly selected from each group, and the expressions of VEGF and bFGF in the endothelial cells of the involved PVC were detected by immunohistochemical staining. Meanwhile, 10 normal New Zealand rabbits served as control. Results: There was only a small amount of VEGF and bFGF expression in the endothelial cells of normal rabbits. In the two experimental groups, the VEGF expressions in the endothelial cells of the involved PVC were significantly increased versus control (all P<0.05), and the increases were progressively greater during the observation period, but the increasing amplitude at each time point in treatment group was significantly greater than that of model group (all P<0.05); the alteration pattern of bFGF was generally similar to that of VEGF, but it reached the peak at 4 d after administration and did not continue to rise. Conclusion: The increased VEGF and bFGF expressions in the endothelial cells may be an endogenous protective action following acute venous thrombosis, and thrombolytic and anticoagulant therapy can promote this action.