The initial investment and enhance the efficient of energy-savings will be reduced by Using assistant cooling composite ground source heat pump system.This paper introduces the climate and the overview of building energy consumption of hot summer and cold winter region and analyses the feasibility of ground source heat pump system using assistant cooling equipment in this region.Taking a building in Shanghai for example,the initial investment and operating cost between assistant cooling composite ground source heat pump system and no assistant cooling ground source heat pump system are compared.The results show that the assistant cooling-source heat pump system has great advantages in the reduction of initial investment and operating cost in this region.