A study was conducted to demonstrate the application of the Brønsted-Evans-Polanyi (BEP) relationship in the analysis of surface elementary reaction steps. The BEP equation directly related the change in activation energy of the reaction, δEact to the corresponding change of the reaction energy, δEr for different surfaces through a constant factor α. The activation energy was deduced from the reaction energy, which was a thermodynamic parameter. An analytic derivation of the BEP equation was presented using a Marcus-type analysis to provide a conceptual frame for the discussion. The physical chemistry of the surface reaction was viewed as a potential-energy curve crossing problem. It was found that surface electronic factors required a modification of this simple potential-energy crossing model.