Abstract: A method for pre-estimating the equivalent electromagnetic parameters of absorbing fiber cloth sheet which has been widely used in fabricating stealth vehicles is presented.The equivalent EM parameters(i.e., permittivity and permeability)are the most important data in design.With the anisotropic property structure of the mixed media,based on the strong fluctuation theory,a set of complex integral equations for EM parameters are formulated.With Fortran 5.1,a system software is set up to search out these unknown parameters by iterative way.Some pre estimating EM parameters examples are listed.