A system for reducing a carbon compound of a heat engine includes: an outlet pipe transferring and outputting an exhaust gas from the heat engine; a removal reacting tank connected to the outlet pipe, the removal reacting tank generating a strong alkaline solution by a reaction of a resource material and a water and removing the carbon compound from the exhaust gas by a contact of the carbon compound and the strong alkaline solution; a sludge storing tank storing a sludge generated by a removal reaction in the removal reacting tank; and a decomposing tank generating the resource material for the removal reacting tank by decomposing the sludge from the sludge storing tank with a heat. Accordingly, since the carbon compound such as carbon dioxide is effectively removed from the exhaust gas emitted from a heat engine equipped in an industrial plant and a vehicle, atmospheric environmental pollution is prevented and regulation on carbon dioxide emission is satisfied.