Sulphoaluminate　cement　has　the　advantage　of　low-temperature　application　performance,　but　its　hydration　mechanism　at　low　temperatures　is　not　yet　clear.　Anhydrous　calcium　sulfoaluminate　(C(4)A(3)S)　is　the　main　mineral　in　the　composition　of　sulfoaluminate　cement　clinkers.　In　this　paper,　C(4)A(3)Smixed　with　gypsum　(CaSO4　center　dot　2H(2)O)　to　form　a　C(4)A(3)S-CSH(2)cement　system;　X-ray　diffraction　(XRD),　thermogravimetric　analysis　(TG-DTG),　scanning　electron　microscopy　(SEM)　and　mercury　intrusion　analysis　(MIP)　to　clarify　the　effect　of　temperatures　on　the　hydration　properties　of　C(4)A(3)S-CSH(2)cement　system.　The　results　showed　that　hydration　of　the　C(4)A(3)S-CSH(2)cement　system　could　carry　on　at　low　temperatures,　even　at　-15　degrees　C.　The　main　hydration　product　was　ettringite.　Low　temperatures　did　not　change　the　types　of　the　hydration　products,　but　the　low　temperature　of　0　degrees　C　was　more　favorable　for　the　formation　of　ettringite.　The　early　hydration　of　the　C(4)A(3)S-CSH(2)cement　system　was　inhibited　by　the　decrease　in　temperature.　However,　hydration　of　the　cement　at　0　degrees　C　continued　at　a　high　rate　after　one　day.　Morphologies　of　the　ettringite　for　the　C(4)A(3)S-CSH(2)cement　system　at　-15　degrees　C　were　needle-like　structures,　while　they　were　of　columnar　structure　at　0　degrees　C.　The　compressive　strength　of　samples　at　0　degrees　C　reached　82　MPa,　which　is　significantly　higher　than　that　at　20　degrees　C.