Calcium　carbide　Slag　is　from　CaC2　hydrolysis　reaction　and　will　do　harm　to　land　and　make　pollution.　Calcium　carbide　slag　can　be　a　substitute　for　limestone　to　produce　clinker　with　a　high　portion　of　CaO　as　an　excellent　calcium　raw　material.　As　a　kind　of　industrial　wastes,　the　properties　of　calcium　carbide　slag　differentiate　from　that　of　natural　limestone.　In　the　present　investigation,　the　modern　analysis　methods　of　XRF,　XRD,　DTA/TG,　petrographic　analysis　were　used　to　compare　carbide　slag　and　limestone,　and　the　results　showed　that　the　main　chemical　compositions　of　the　calcium　carbide　slag　were　basically　the　same　with　that　of　natural　limestone.　Comparing　with　limestone　materials,　calcium　carbide　slag　had　a　higher　content　of　CaO,　and　the　main　mineral　phase　constituent　of　limestone　was　CaCO3,　whereas　the　main　mineral　of　calcium　carbide　slag　was　Ca(OH)(2)　with　a　lower　decomposition　temperature.　It　has　been　found　that　under　the　same　temperature　the　amount　of　C3S　in　the　clinker　of　calcium　carbide　slag　batching　was　slightly　less　than　that　of　limestone　batching.