Temporal-spatial Oversampling(TSO) system has unique advantage for infrared point target detection. Infrared point target imaging simulations and experiments were designed. The shapes and energy distribution of point target in infrared image which were taken by TSO and ordinary sampling systems were researched. The point target imaging features were verified by the simulations and experiment results. First, principle of TSO system for point target imaging was compared with principle of ordinary sampling system, the main difference of the two sampling system was the arrangement of infrared detector’s pixels. The arrangement of pixels in TSO system used half-sensor-alignment to improve the efficiency of point target energy collection. Then, imaging models of TSO and ordinary sampling system were built for simulations of point target imaging by two systems. The two systems characteristics were researched by simulations. And also the statistical characteristics of maximum pixels were analyzed. Simulation results show TSO system can get more stable point target imaging. Finally, infrared point target imaging experiments of two system were designed. The experiment results show that the temporal-spatial oversampling system can overcome the bad influence by phase noise. And the target images also have special characteristics in temporal-spatial oversampling system. These characteristics can make the infrared point target detection more effectively.