Based on the equivalence of the modulation transfer function (MTF) of a plane parallel turbid medium and the emergent light intensity distribution from the medium under isotropic diffuse illumination, the MTF of some typical turbid media is fully evaluated through numerical solution with a radiation transfer code DISORT. General MTF characteristics in the whole spatial frequency range are obtained. It is found that the MTF behavior depends not only on the scattering and absorption optical thickness of the medium but also on the scattering phase function. General features of the dependence of MTF on the optical thickness, the scattering phase function, the single scattering albedo, and the asymmetric factor are presented.