简介：Uptonow,detailedstrategiesandalgorithmsofautomaticchangedetectionforroadnetworksbasedonGIShavenotbeendiscussed.Thispaperdiscussestwodifferentstrategiesofautomaticchangedetec-tionforimageswithlowresolutionandhighresolutionusingoldGISdata,andpresentsabufferdetectionandtracingalgorithmfordetectingroadfromlow-resolutionimagesandanewprofiletracingalgorithmfordetectingroadfromhigh-resolutionimages.Forfeature-levelchangedetection(FL-CD),aso-calledbufferdetectionalgo-rithmisproposedtodetectchangesoffeatures.SomeideasandalgorithmsofusingGISpriorinformationandsomecontextinformationsuchassubstructuresofroadinhigh-resolutionimagestoassistroaddetectionandextractionaredescribedindetail.