An analysis by the integral equation method has been performed on the radiative transfer in the plane-parallel fibrous media, in which the axes of scatterers are mutually parallel, under collimated incoming light. It is found that the intensities of the incident radiation in the media increase with the albedo ω and their distributions tend to have maxima in the vicinity of the boundary as ω and their distributions tend to have maxima in the vicinity of the boundary as ω asymptotes to unity. The resulting distributions of the incident radiation and the radiative heat flux are compared with the solutions obtained by the Lick’s type exponential kernel approximation and thereafter the validity of this approximation is examined in some detail. Further the modified Lick’ s meth resented and illustrated to show goo agreem the exact solution for wide range of parmeters. The exact solution for wide range of parameters. The radiation extinction function appeared in the present system is properly described by the Bickley-Naylor’ function, Kin X and some integral relations on Kin x are presented.