The operating range model of the infrared polarization imaging system was established based on the minimum resolvable temperature difference(MRTD) between the target and the background. The impact of the background clutter on the operating range was also analyzed. Simulation results show that the operating range is concurrently dependent on the target/background polarization characteristics, atmospheric transmission and the observation geometry. Among these factors, the background clutter greatly affects the operating range of infrared polarization imaging system. Besides, polarization imaging mode and intensity imaging mode may have different advantages compared with each other under different imaging conditions.