A boundary layer flow of a viscous in compressible and electrically conducting fluid past an infinite vertical porous plate has been considered. Exact solutions to the dimension less governing equations have been obtained by using the single and multiple parameter perturbation technique. Finite difference method and also Laplace transform method. Thermo diffusion effect on an unsteady simultaneous convective heat and mass transfer flow of an in compressible, electrically conducting, heat generating/absorbing fluid along a semi infinite moving porous plate.