In high speed flight, the aero-optical effect greatly affects infrared imaging system. An experiment investigating heating window radiance was conducted based the fluid computational simulation results. The paper gave the facilities needed and the procedures for experiment performance. The experiment data was analyzed by means of target signature evaluation principle, target contrast, SNR, gray level correlation index and gradient correlation index was computed from 4-bars infrared image. The results showed that the image region of interest was greatly affected by the heating window radiation. And some pre-processing skills should be introduced before implementing the target recognition and tracking algorithms. It is meaningful for validating performance of infrared imaging system with non-cooling window and to development methods of suppressing the hot dome radiation to reduce the image degradation.