The present invention relates to a combined heat and power system for greenhouse carbon dioxide enrichment, and more particularly, to a combined heat and power system for greenhouse carbon dioxide enrichment which 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 including: a unified pipe system 130 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 190 configured to store the carbon dioxide transmitted to demand destinations along with the hot water; and supply means 192 and 220 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, whereby it is possible to save the facility costs and the power costs for transmission by transmitting carbon dioxide and hot water using the unified system and improve the operation efficiency and the marketability by applying the combined heat and power system to various buildings in addition to the greenhouse 200.