This work presents the study of the conversion of model mixtures of C6-, C14-alkanes and a diesel fraction over ZSM-containing catalyst modified with manganese, lanthanum and zinc additives. Physico-chemical methods, including TEM and IR, are applied for the characterization of the catalysts used. The presence of Brönsted and Lews acid centers as M0 - or Mn+-metal centers is identified. It is found that the structure of the acid centers can include MnSiO3, La5Si, Mn15Si26, LaMn2Si2, La Al11O18, La2Si2O7, La3Si2, functioning as Lewis acid centers. The results of the study show that the degree of conversion of hexane and tetradecane as well as the composition of the resulting compounds are determined by the length of the hydrocarbon chain and the conditions of the process.