The　Joule　heating　behavior　of　the　carbon　fiber/epoxy　composite　(CF/EP)　was　studied　in　this　work,　as　well　as　their　influence　on　the　in-situ　mechanical　properties　of　the　composites　and　their　de-icing　performance.　The　equilibrium　temperature　of　the　CF/EP　composite　could　be　conveniently　adjusted　by　tuning　the　current　according　to　the　Joule＇s　law.　Dynamic　mechanical　analysis　(DMA)　tests　indicated　that　the　rigidity　and　stiffness　of　the　fiber-reinforced　composite　decreased　with　increasing　temperature,　and　the　glass　transition　temperature　(Tg)　of　the　composites　was　around　104　degrees　C.　It　was　found　that　the　flexural　properties　of　the　composites　in　situ,　measured　under　the　electric-current　loading,　depended　on　the　current　value　in　the　range　of　room　temperature　to　Tg.　With　increasing　the　loading　current,　either　the　flexural　modulus　or　strength　of　CF/EP　decreased　gradually.　Such　results　could　be　explained　that　the　higher　current　loading,　the　larger　Joule　heat,　led　to　the　higher　operating　temperature　of　the　composite　samples　and　the　evolution　of　their　mechanical　properties　accordingly.　Vickers　hardness　tests　indicated　that　the　micro-hardness　of　the　composite　decreased　with　the　increase　of　the　operating　temperature,　which　coincided　with　the　evolution　of　its　flexural　properties　with　the　electric-current　loading.　The　dependence　of　the　failure　behaviors　of　the　CF/EP　on　the　loading　current　was　revealed　by　the　analysis　of　their　fractured　surface,　where　micro-buckling,　kinking,　fiber　pull-out　and　breakage　were　involved.　A　preliminary　study　indicated　that　less　energy　was　consumed　for　the　deicing　of　the　same　amount　of　the　ice　with　the　CF/EP　composite　in　the　case　of　less　electric-current　loading.　The　research　on　the　Joule　heating　effect　of　CF/EP　and　their　corresponding　mechanical　properties　benefits　the　design　and　direct　application　of　the　composites　under　the　electric-current　loading.