Abstract: In this paper, an empirical method based on two atom-parameter equations is developed. The initial heats of chemisorption for H2 and O2 on transition d-metals are successfully evaluated. Furthermore, the energy of activation of surface chemisorption of oxygen with transition d-metals surfaces are empirically calculated using a bond energy bond order (BEBO) approach. The agreement of the calculated results with the experimental data is satisfactory. The metals are then calssified approximately into three groups, A,B and C,in which the chemisorption properties are different from each other.