Abstract: Based on the response characteristics of the avalanche photodiode array (APD), a 1-D point process model of the photon counting imaging was established by using the statistics description of the random points. The effects of the photon density, APD′s quench time, gate time and sample periods on the quality of the photon counting imaging were analyzed with the random sample theory of Poisson point process. The qualities of photon counting imaging was simulated at different photon density in the near-infrared band with Monte Carlo simulation method. The simulation results are presented.