Objective：To evaluate the effects and safety of thrombolysis combined with anticoagulation therapy in the treatment of sub－massive pulmonary embolism（SPE）. Methods：Published literatures concerning randomized controlled trials（RCTs） of thrombolysis combined with anticoagulation therapy for patients with SPE were retrieved from PubMed，EMbase，Cochrane Library，CNKI，CBM and WanFang database by computer and handsearch was used to collect other studies before the deadline of June 2013. According to the inclusive and exclusive criteria，literature and data were independently screened and extracted by two researchers，meanwhile，the quality of the included studies was assessed. Meta analysis was conducted by RevMan 5.0 software. Results：A total of nine RCTs including 861 patients with SPE were enrolled. Meta analysis demonstrated that：①thrombolysis combined with anticoagulation therapy could improve the overall efficiency of patients with SPE（OR＝5.97，95％CI=3.51 to 10.15），P=0.000）.②thrombolysis combined with anticoagulation therapy could effectively improve PaO2，PaCO2，P（A-a）O2，respiratory rate and heart rate（P＜0.05）. Conclusion：Avail－able data indicate that the overall efficiency，arterial blood gas and clinical symptoms of patients with SPE can be improved by throm－bolysis combined with anticoagulation therapy than by anticoagulation alone. Moreover，safety needs further study due to the quality of included studies.