Calcium　carbide　slag　can　be　a　substitute　for　the　natural　limestone　to　produce　cement　clinker　and　also　with　a　high　portion　of　CaO　as　an　excellent　calcium　raw　material.　Thus,　it　not　only　reduces　the　pollution　that　the　calcium　carbide　slag　brings　to　the　environment,　but　also　reduces　the　exploitation　of　non-renewable　resource-limestone.　The　main　mineral　constituent　of　calcium　carbide　slag　is　Ca(OH)(2),and　there　are　many　differences　in　decomposition　temperatures　between　the　calcium　containing　raw　materials.　When　calcium　carbide　Slag　is　added,　the　forming　process　of　cement　clinker　and　the　major　reactions　happened　in　that　process　changes.　The　empirical　equation　for　calculating　forming　heat　of　cement　clinker　made　of　limestone　is　no　longer　applied　for　those　made　of　calcium　carbide　slag.　In　this　paper,　the　empirical　equation　for　forming　heat　calculation　of　calcium　carbide　slag　added　cement　clinker　is　researched　and　rebuilt　under　the　principles　of　thermodynamics.　Results　show　that　the　change　of　raw　materials　has　a　great　influence　on　the　forming　heat　of　cement　clinker.　When　the　traditional　raw　materials　are　replaced　by　calcium　carbide　slag,　the　forming　heat　of　cement　clinker　will　be　reduced.　Calculating　the　forming　heat　by　the　revised　empirical　equation　can　help　reduce　errors　and　make　calculation　results　near　the　reality　and　then　convenient　for　evaluation　of　heat　efficiency.　The　work　provides　some　theoretical　underpinnings　for　the　process　analysis　and　calculation　of　forming　heat　of　cement　clinker　made　from　calcium　carbide　slag.