Using　the　numerical　simulation　technique,　the　authors　study　the　effect　of　the　specimen　size　on　the　stress　distribution　and　fracture　properties　of　the　interface　between　the　fiber　and　matrix　for　the　fiber　pull-out　test.　The　effects　of　the　embedded　length　of　the　fiber　in　the　matrix　and　the　wrapped　thickness　of　the　matrix　around　the　fiber　are　considered.　On　the　assumption　of　the　perfect　interface　of　fiber　and　matrix,　the　numerical　analysis　for　the　interfacial　shear　stress　and　normal　stress　of　the　test　specimen　with　different　dimensions　is　performed.　For　the　whole　process　of　interfacial　crack　growth,　the　energy　release　rate　is　calculated.　All　materials　are　assumed　to　be　linearly　elastic　solid.　It　is　shown　that　the　size　of　the　test　specimen　affects　dramatically　the　distribution　of　stresses　and　the　fracture　properties　of　the　interface.