Inthispaper,wepresentanovelregion-basedactivecontourmodelbasedonglobalin-tensityfittingenergyinavariationallevelsetframework.Meanwhile,aninternalenergytermisin-troduced,anditforcesthelevelsetfunctiontobeclosetoasigneddistancefunction.Imageglobalinformationutilizedefficientlymakestheproposedmodelinsensitivetonoise,andtheintroducedpenaltytermcanavoidthecostlyre-initializationfortheevolvinglevelsetfunction,whichnotonlyspeedsupthecontourevolvement,butalsoimprovesaccuracyofthefinalcontour.Comparisonswithotherclassicalregion-basedmodels,suchasChan-VesemodelandRegion-ScalableFitting(RSF)model,showtheadvantagesofourmodelintermsofefficiencyandaccuracy.Moreover,themodelisrobusttonoise.