The present invention relates to the use of plasminogen in the dissolution of fresh and old thrombus. Compared with other existing thrombolytic drugs, the plasminogen of the present invention can specifically dissolve thrombus without causing side effects such as bleeding. The drug of the present invention also has the advantages of dissolving both fresh and old thrombus, with a long half-life and controllable thrombolytic strength. Therefore, plasminogen may become a brand-new strategy for dissolving thrombus in vivo.
