The efficient utilization of the waste heat with mid-low temperature from the combined heating and power (CHP) system is crucial for the improvement of the energy efficiency. In the CHP system, the waste heat with mid-low temperature was directly used to generate domestic hot water or heat by the heat exchanger. Different from common methods, in this paper a new utilization approach of the waste heat with mid-low temperature by integrating the CHP system and the ground source heat pump (GSHP) was proposed, and a new coupling system was designed based on the integrating mechanism. Numerical simulations were implemented to investigate the performances of the proposed coupling system. The influence characteristics of the temperature of the warm water generated by the GSHP on system performances, including the coefficient of performance (COP) of the GSHP, the heat output and the total energy efficiency, were revealed. The results showed that with the same input and heat output, the proposed system can generate more power than the reference system, and the total energy efficiency and the COP of the GSHP were simultaneously improved. (C) 2015 Elsevier Ltd. All rights reserved.