Objective: To study the therapeutic approach of alteplase to lower extremity deep vein thrombosis (DVT), as well as its efficacy and safety. Methods: The clinical data of 23 patients with lower extremity DVT admitted to our hospital and treated with altepalse from May 2005 to May 2010 were retrospectively analyzed. All the patients presented with a first onset of unilateral symptoms of lower-extremity DVT, their ages were less than 75 years and onset of illness had occurred within 21 days. Results: The thrombolytic therapy using alteplase resulted in short-term beneficial effects on DVT patients. Seventeen patients (73.9%) achieved clinical cure and 6 patients (26.1%) had clinical improvement. The major complication during infusion of alteplase was bleeding which was mainly seen at the needle puncture sites and gums, but no fatal bleeding events such as the massive visceral or intracranial hemorrhage occurred. All the 23 patients were followed up for a period of 3 to 48 months. Of whom, 17 cases (73.9%) recovered completely, 5 cases (21.7%) developed post-thrombotic syndrome, and 1 case died of cardiac infarction. Conclusions: The thrombolytic therapy using alteplase has remarkable efficacy for the treatment of DVT, and the clinical improvement may be obtaind even if the disease course of the patientis is more than two weeks. Although bleeding is the most common adverse event, it is safe for patients to receive the intermittent intravenous administration of alteplase in three days.