Effects　of　disodium　EDTA　(EDTA-2Na)　on　hydration　and　mechanical　properties　of　calcium　sulphoaluminate-belite　cement　(CSBC)　were　investigated　systematically.　Results　show　that　EDTA-2Na　addition　leads　to　visible　changes　in　CSBC　strength　development.　0.50　%　EDTA-2Na　significantly　enhances　the　compressive　strength　by　18　%　and　23　%　compared　with　the　blank　specimens　at　7　d　and　28　d,　while　reducing　the　strength　at　8　h　and　1　d.　The　content　of　the　main　hydration　product　(AFt)　determines　the　strength　development.　At　the　early　hydration　stage,　EDTA-2Na　delays　hydration　of　ye＇elimite　to　form　AFt,　thus　decreasing　the　early　hydration　degree　of　CSBC　and　increasing　the　porosity　to　reduce　strength.　In　the　presence　of　EDTA-2Na,　the　morphology　changes　of　amorphous　aluminum　hydroxide　(AH3)　facilitate　the　AH3-C2S-CaSO4　reaction　to　increase　AFt　content　and　form　a　more　condensed　structure,　thus　enhancing　the　late　strength.　In　this　way,　the　strength　development　of　CSBC　mortars　can　be　modified　and　regulated　by　EDTA-2Na.