Objective To explore the therapeutic effect of catheter-directed thrombolysis combined with vena cava filter on deep venous thrombosis (DVT) of lower extremity.Methods The clinical data of 65 patients with DVT of lower extremities from January 2008 to August 2009 were analyzed retrospectively, whose course of diseases were not more than 7 d and clinical type included central type and mixed type. Thirty-two cases were treated with catheter-directed thrombolysis combined with vena cava filter, while administrating treatment of anticoagulation and activating blood circulation to dissipate blood stasis, which were named as study group. Thirty-three cases were treated traditionally with thrombolysis, anticoagulation, and activating blood circulation to dissipate blood stasis, which were named as control group. The course of therapy was continued 10-14 d, then the efficacy in two groups patients was evaluated. Results It was (7.35±1.42) cm that circumference difference before treatment between affected extremties and unaffected extremties in study group, which of 3, 7, and 14 d after treatment was (4.21±1.12) cm， (2.87±0.98) cm, and (1.22±1.02) cm, respectively. Circumference difference between before and after treatment had significant difference in study group (Plt;0.01). It was (6.97±1.27) cm that circumference difference before treatment between affected extremties and unaffected extremties in control group, which of 3, 7, and 14 d after treatment was (5.72±1.31) cm, (4.58±0.88) cm, and (3.18±1.24) cm, respectively. Circumference difference between before treatment and 3, 7, and 14 d after treatment had significant difference in control group (Plt;0.05 or Plt;0.01). Circumference difference before treatment in two groups had no significant difference (Pgt;0.05). Circumference difference after treatment at different time points in two groups was significantly different, respectively (Plt;0.01). Circumference difference after treatment at different time points in study group was significantly less than that in control group, respectively (Plt;0.01). After 14 d, complete recanalization rate （71.88%, 23/32） and cure rate (71.88%, 23/32) of iliofemoral vein in study group were significant higher than that (36.36%, 12/33) in control group (Plt;0.01). No pulmonary embolism occurred. Conclusion In terms of ideal therapy targets of DVT of lower extremity, the catheterdirected thrombolysis combined with vena cava filter is obviously superior to traditional thrombolysis treatment.