According to the urgent requirements for the winter heating in a rural residential in Chongqing, it has set up air-source heat pump heating system experiment platform. From the perspective of supply and return water temperature, power consumption, heat supply and coefficient of performance (COP), it has analyzed the system performance factors and phase characteristics (including starting, stable operation and whole stage) during operation, and the system has been very different characteristics in this three stages. Primarily, the initial temperature of the starting phase has obviously influenced COP of the system and when defrosting, it has a 25% drop in performance of the system. For stable operation of the stage, the performance and the initial temperature are not related. Reducing the set temperature, the COP has increased significantly, when there has been a good outdoor condition. Overall, COP in starting stage is the highest, then the whole stage, and COP of stable operation is lowest.