This paper is a study to solve the practical problem of comparing two catalysts experimentally. The process under discussion is the isomenzation of aromalics of C8 in non-equilibrium mixtures lo near equilibrium concentrations to allow a greater yield in the production of ortho- and para-xylene. To define the zone of work of each catalyst, the experimental strategy used was the Response Surface Methodology. The catalytic parameters studied were the activity, and selectivity through the analysis of the operating variables influence, the reaction products and the building of empirical models.