The heat and mass transfer characteristics of natural convection about a horizontal surface embedded in a saturated porous medium is analyzed. An integral procedure is derived to the heated horizontal surface, where surface temperature and surface concentration are power function of distance from the leading edge of porous plate. Local Nusselt number and local Sherwood number variations in the boundary layer are presented graphically and in the tables for the various values of problem parameters and it is found that the temperature and concentration fields near the plate increases with power law exponent n. (c) 2009 Elsevier Ltd. All rights reserved.