The influence of the ratio between the hydrogenating-dehydrogenating and acidic functions of bifunctional catalysts prepared from crystalline aluminosilicates and silicaaluminophosphates of different structural types on the selectivity of n-hexadecane transformation in a hydrogen atmosphere was studied. The ratio of the hydroisomerization to hydrocracking products was shown to be determined by the ratio of the acidic to hydro-dehydrogenating activities of the catalyst and the structural characteristics of the initial zeolite or silicaaluminophosphate. The dependence of the amount of isoparaffins on the crystallographic size of channels of the base zeolite is nonmonotonic in character, with a maximum at 0.62-0.63 nm, which corresponds to the kinetic diameter of monomethylisoparaffins.