The water fog is a novel jamming material with wider jamming band, cheap cost and non side effect to the creature and environment. Using the Mie Scattering Theory, mass extinction coefficients (MEC) of the water fog with lognormal distribution and normal distribution are calculated in visible-light band, in IR transmission windows and at two military laser wavelengths. The extinction characteristics of the above bands and the lengths are obtained. The relationship between the calculated results and the parameters of the size distribution is analyzed.