Abstract: Objective:To explore the characteristics of lower limb deep venous blood flow of perioperative patients with pelvic tumor using color doppler flow image(CDFI).Methods:Thirty-five perioperative pelvic tumor patients with lower extremity pain and swell were were detected using CDFI.The diameter and velocity of femoral vein in patients without deepveinthrombosis(DVT) were observed,and which was reexamined at 3 to 10 days after operation.Results:DVT in 11 cases and no-DVT in 23 cases were found before operation.Compared with postoperation,the interior diameter of femoral vein widen,the velocity of femoral vein sloweddown,and the average maximum velocity of femoral vein during the quiet breathing decreased before operation(P0.01).Conclusions:It is important to examine the lower limbs vein of perioperative patients with pelvic tumor using CDFI,especially for the patients with malignancy,which can early diagnose the DVT and know the lower limb deep venous blood flow of patients.