The　properties　of　magnesium　phosphate　cement　(MPC)　are　studied　by　measurements　of　setting　time,　flowability,　compressive　strength　and　by　multiple　technique　analyses　of　pH　values,　calorimetry,　XRD,　TG,　MIP　and　SEM　taking　calcium　lactate　(CL)　content　as　variables.　Results　show　that　CL　can　significantly　prolong　the　setting　time　and　promote　the　synergetic　development　of　compressive　strength　of　MPC,　but　the　addition　of　CL　leads　to　a　decrease　in　flowability　of　MPC.　Comprehensive　consideration　on　these　properties,　the　optimal　dosage　of　CL　is　5%.　In　this　case,　the　setting　time,　flowability　and　1　day　&　28　days　compressive　strength　of　MPC　are　84　minutes,　185　mm,　40.8　MPa　&　54.2　MPa,　respectively.　Multiple　technique　analyses　show　that　the　addition　of　CL　can　decrease　the　liquid　phase　pH　value　and　hydration　rate　of　MPC,　resulting　in　the　extension　of　setting　time.　A　low　content　of　CL　(3%)　can　improve　the　reaction　degree　and　optimize　the　matrix　pore　structure　of　MPC,　and　thus　promoting　the　strength　development　(50.90　MPa　increased　to　65.93　MPa).　However,　an　excessive　addition　of　CL　(7%)　will　lead　to　the　decrease　in　reaction　products　and　the　increase　in　matrix　porosity　of　MPC,　resulting　in　a　decrease　in　compressive　strength　(43.30　MPa　reduced　to　37.36　MPa).