The　present　work　develops　a　numerical　method　for　analysis　of　the　microstructure　and　property　evolution　in　the　hydration　of　the　cement.　A　time-dependent　micro-mechanical　model　is　established　to　investigate　the　microstructure　development　and　the　effective　property　evolution　of　the　cement　paste,　while　the　input　parameters　of　the　model　are　based　on　experimental　data.　It　is　assumed　that　the　cement　paste　composite　consists　of　the　anhydrous　cement　particles,　cement　gel　and　pores.　The　cement　particles　have　a　periodically　spatial　array　and　are　wrapped　by　the　cement　gel.　The　Young＇s　modulus　and　Poisson＇s　ratio　of　the　cement　paste　are　calculated　by　direct　average　method　and　two-scale　expansion　method.　The　comparisons　between　the　numerical　results　and　experimental　data　show　that　this　model　can　simulate　the　evolution　of　the　microstructure　and　properties　during　the　hydration　of　the　cements　quite　satisfactorily.　(C)　2005　Elsevier　Ltd.　All　rights　reserved.