Objective　To study the efficacy of inferior vena cava filter (IVCF) placement and catheter-guided thrombolysis on deep venous thrombosis (DVT) in lower extremities.　Methods　Forty-two patients with acute DVT in lower extremities (20 males and 22 females) at the age of 22-79 years ( mean 48±15 years) admitted to our department from June 2008 to January 2010，were randomly divided into groups A，B and C in the order of their admission time

14 patients in each group. Patients in group A received system

ic thrombolysis and anticoagulation therapy after IVCF placement. Patients in group B underwent anticoagulation therapy and catheter-guided thrombolysis after IVCF placement. Patients in group C received only anticoagulation therapy.　Results　The difference was reduced in circumference of healthy and affected lower extremities after treatment. The resolution time of swelling in affected extremity was shorter in group B than in groups A and C (P＜0.01). The thrombi were completely disappeared in 5 patients (38.71%) of group B. The resolution time of thrombi was shorter in group B than in groups A and C (P＜0.01). The mean dose of urokinase used in group B was（1.56±5.80）×10

6

units

which was significantly lower than that used in group A（P＜0.01）. Gross hematuria was observed in 1 patient and displacement of IVCF occurred in 1 patient of group A

respectively. Pulmonary embolism (PE) occurred in 1 patient of group C. Thirty-four patients were followed up for 6-18 months

during which no PE and displacement of IVCF were found，except for deep vein dysfunction in lower extremities of 1 patient in group B.　Conclusion　IVCF placement and catheter-guided thrombolysis are a safe and effective procedure for acute DVT in lower extremities.