Heightextractionforbuildingsisafundamentalstepof3Dscenereconstructioninmanyvirtualrealityapplications.Inthispaper,weproposeanautomaticmethodtoextracttheheightofbuildingsinhighresolutionsatelliteimagerybasedonthelengthofshadow.Takingintoaccountthelimitationoftraditionalalgorithms,wemakeuseoftheboundaryinformationofabuildingtofacilitatedetectingandmatchingtheshadowregionswithhigheraccuracy.Then,weintroduceashadow-castmodeltocorrecttheshadowlocationinoursystem.Theexperimentalresultshowsthatwhenextractingtheheightofbuildingsfromcomplexurbanregions,ourmethodhasbetteraccuracy.