Vascular disrupting agents (VDAs) have presented a new kind of anti-cancer drug in recent years.  VDAs take advantage of the weakness of established tumor endothelial cells and their supporting structures.  In contrast to anti-angiogenic therapy, which inhibits the outgrowth of new blood vessels, vascular targeting   treatments selectively attack the existing tumor vasculature.  Here we summarized the anti-tumor activities, mechanisms and clinical applications of small molecule VDAs.