In　order　to　overcome　the　shortcomings　of　precast　composite　beams,　such　as　easy　cracking　in　post-cast　zone,　poor　ductility,　and　easy　to　damage,　engineering　cementitious　composites　(ECC)　were　used　in　the　precast　plate　and　post-cast　area　of　composite　beams.　Bending　tests　were　carried　out　on　11　beam　specimens.　The　flexural　properties　and　effects　of　the　ECC　plate　thickness,　connecting　method　of　reinforcement,　and　reinforcement　ratio　on　the　flexural　properties　were　investigated.　Bearing　capacity　and　displacement　of　its　characteristic　point　were　studied.　The　crack　width　was　measured　and　the　laws　of　crack　development　trend　and　damage　evolution　were　analyzed.　The　results　show　that　the　load,　displacement,　and　ductility　of　the　precast　beams　with　ECC　plate　and　post-cast　joints　under　cracking,　yielding,　and　ultimate　condition　were　higher　than　those　of　RC　beams.　The　thicker　the　ECC　plate　was,　the　more　significant　the　effect　was.　The　reinforcement　connection　methods　of　steel　sleeve　and　hoop-inserting　could　effectively　transfer　the　reinforcement　stress.　The　precast　beam　could　effectively　control　the　crack　width　in　bending　area,　and　the　damage　index　was　larger　when　it　was　damaged.　However,　it　could　still　bear　load　when　the　damage　was　serious,　which　is　suitable　for　the　key　joint　of　precast　structure.　©　2019,　Editorial　Board　of　Journal　of　Harbin　Institute　of　Technology.　All　right　reserved.