Abstract: Infrared scene projector is the scene sources equipment which provides infrared target and background for infrared imaging system. In order to test the performance of infrared scene generator, the minimum resolvable temperature difference (MRTD) theoretical model of infrared scene generator is established, and a testing system has been designed base on the theoretical model. The testing system first generates a spatial frequency standard signal. Temperature distribution is measured by scanning radiometer. Changing the frequency and measuring the temperature difference between the target and background until the frequency with the condition that measured contrast is less than 20%, the MRTD is just the temperature difference between rod-shaped target and background at that spatial frequency. Then the curve of MRTD versus spatial frequency can be obtained. The experimental results show that the developed system can test MRTD for infrared scene simulation system with the advantages of easy to operate, reliable, good maintenance and friendly human-computer interface and so on.