Abstract: To investigate operating characteristics of the pump-driven two phase loop integrated with the refrigerating system, especially the heat exchanging performance changing with pump frequency and temperature difference between indoor and outdoor, an experimental setup of the integrated refrigerating system was established. In this setup, a 2.63 kW compressor and a 3.75 kW compressor were used in the vapor compression refrigerating system, respectively. And an inverter pump was used in the pump-driven loop. Results show that the heat exchanging performance of the integrated system increases when the pump frequency is below 35 Hz, and then decreases with the frequency at the indoor temperature of 25℃ and the outdoor temperature of 10℃, while the energy efficiency ratio changes slightly with the frequency in the beginning and afterwards decreases gradually. When the outdoor temperature varying from 0℃ to 30℃, the variation tendency of the performance for the integrating system was investigated and the optimum outdoor temperature for switching the operating modes was obtained.