Convective heat transfer through a vertical multilayered porous media is examined numerically. The examination is focused upon the effect of the nonuniform permeabilities of the sublayers, with vertical isothermal walls at different temperatures and horizontal perfect insulated walls. The study was done for α 3 layered porous medium in which the first and third layers have equal thicknesses and permeabilities, for a range of the permeability ratio Kr, of the core region from 0.1 to 10 and a range of the width ratio of the inner sub-layer to the total width (Wr ) varies form 0.0 10 1.0. This part is concerned with the effect of the variable permeabilty on the temperature and flow fields and the second part of this work (14), is concerned with the effect of the variable permeability porous layers on the heat transfer. The governing equations have been written in terms of nondimensional variables and were solved using the finite difference method. A comparison is made with the results obtained by Lauriat and Prasad (13). The comparison shows a very good agreement for the present results and hence proves the validity of the model. The results give a very good idea about the effect of the inhomogenity of the porous medium on the flow structure and temperatures.