A combined heat and power system for greenhouse carbon dioxide enrichment purifies carbon dioxide from exhaust gas of the combined heat and power system generating and supplying power and heat by combusting fuel and supplies the purified carbon dioxide to a greenhouse. The combined heat and power system includes a unified pipe system configured to simultaneously transmit hot water and carbon dioxide through a single pipe by dissolving the purified carbon dioxide in a heat transmission medium, a storage system configured to store the carbon dioxide transmitted to demand destinations along with the hot water, and supply unit configured to supply the carbon dioxide transmitted to and stored in the demand destinations depending on a heat and carbon dioxide load condition of a demand destination.
