Fog droplet particles have severe absorption and scattering effects on infrared radiation.Researching its attenuation characteristics is important for improving the performance of weapons in fog.Based on the CART software, the Beer-Lambert law, the Mie scattering theory and the spectral distribution function of the particle group of fog droplets, the transmittance of infrared radiation through the fog particle group was calculated.The attenuation characteristics of infrared radiation in advection fog and radiation fog were analyzed respectively.Taking the 1.064 μm near-infrared radiation, 3.8 μm mid-infrared radiation, and 10.6 μm far-infrared radiation in the light fog environment as the example, and by use of the field data from three Chinese regions, the effects of visibility, transmission distance, the wavelength of the incident light, and the transmittance in clear atmosphere on the overall transmittance of advection fog and radiation fog were analyzed.The results show that:1) Under the condition of light fog, the attenuation in radiation fog is less than that in advection fog;and 2) The 10.6 μm far-infrared radiation has satisfying transmission performance, on which the regional atmospheric parameters have great influence.