The　finite　element　modeling　and　fracture　mechanics　concept　were　used　to　study　the　interfacial　fracture　of　a　FRP-concrete　hybrid　structure.　The　strain　energy　release　rate　of　the　interfacial　crack　was　calculated　by　the　virtual　crack　extension　method.　It　is　shown　that　the　crack　growth　has　three　phases,　namely,　cracking　initiation,　stable　crack　growth　and　unstable　crack　propagation.　The　effects　of　geometric　and　physical　parameters　of　the　hybrid　beam　on　the　energy　release　rate　were　considered.　These　parameters　include　Young＇s　moduli　of　the　FRP,　the　concrete　and　the　adhesive,　thickness　of　the　FRP　plate　and　adhesive,　and　the　distance　of　FRP　plate　end　from　the　beam　end.　The　numerical　results　show　that　the　energy　release　rate　of　the　interfacial　crack　is　influenced　considerably　by　these　parameters.　The　present　investigation　can　contribute　to　the　mechanism　understanding　and　engineering　design　of　the　hybrid　structures.　(C)　2005　Published　by　Elsevier　Ltd.