Abstract: Objective: To investigate the reasonableness of diagnosis and treatment of deep venous thrombosis after operation on iliac-rector carcinoma.Methods: The thrombosis limb was given cold compress and elevation 15°-30°.The thrombosis limb was given hot compress and anticoagulant therapy at 72 h after cold compress.Results: Eight of 12 patients with legs edema were cured during the two weeks.Two months later,by colour doppler examination all the patients were recovered.Conclusions: The preventive measures should be taken before and after operation.The thrombolysis and low-dose anticoagulant are effective in treatment of the malignant venous embolus good and the recurrence rate is very low.