The influence of variation of bare ground terrain emissivity on its infrared radiance statistics under wind conditions is analyzed by Monte-Carlo simulation. The radiance is governed by the heat balance equation in which the sensible heat exchange and sky thermal radiation are under consideration. The results show that, because of emissivity variation, the contrast of a thermal image of bare ground terrain will become sharp obviously and the skewness and kurtosis of the radiative temperature distribution will also change accordingly.