An inverse radiation analysis for simultaneous estimation of the single scattering albedo, the optical thickness and the phase function, from the knowledge of the exit radiation intensities is presented. A genetic algorithm is adopted as the optimizer to search the parameters of the radiation system. The study shows that the single scattering albedo and the optical thickness can be estimated accurately even with noisy data. The estimation of the phase function is more difficult than that of the single scattering albedo and the optical thickness.