Aims:　The　study　aims　to　investigate　the　effect　of　plasminogen　activator　inhibitor　1　(PAI-1),　a　primary　inhibitor　of　fibrinolytic　process,　on　blood　glucose　in　type　2　diabetes　mellitus　(T2DM)　and　its　mechanism.　Materials　and　methods:　We　developed　a　highly　potent　and　highly　specific　PAI-1　inhibitor,　named　PAItrap3,　based　on　the　inactivated　urokinase.　Meanwhile,　a　single　point　mutation　of　PAItrap3　(i.e.,　PAItrapNC)　was　parallelly　prepared　as　negative　control.　PAItrap3　was　intravenously　injected　into　type　2　diabetic　(T2D)　mice　and　its　effect　on　metabolic　system　was　evaluated　by　measuring　the　levels　of　blood　glucose,　PAI-1,　and　tumor　necrosis　factor　alpha　(TNF-alpha)　in　T2D　mice.　Key　findings:　PAItrap3　significantly　reduced　the　high　blood　glucose　level　and　PAI-1　level　in　streptozotocin-induced　T2D　mice.　PAItrapNC　did　not　have　any　hypoglycemic　effect　at　all　on　T2D　mice.　Mechanistically,　both　PAI-1　and　TNF-alpha　levels　were　attenuated　by　the　administration　of　PAItrap3.　In　addition,　we　observed　that　PAItrap3　reduced　the　amount　of　fat　droplets　in　adipocytes.　Significance:　These　findings　provide　clear　evidence　for　PAI-1　to　participate　in　inflammation　and　obesity　mediated　hyperglycemia,　and　open　up　a　new　prospect　for　the　treatment　of　T2DM　by　PAI-1　inhibition.