At many oil refineries and gas processing plants, the C-2-C-5 fractions obtained as by-products do not have any qualified application. These hydrocarbons can be converted into valuable products on zeolite-based catalysts from the pentasil family. The characteristics of conversion of mixed C-2-C-4 olefins and paraffins into aliphatic and aromatic C5+ hydrocarbons in the presence of a galloaluminosilicate catalyst with the structure of pentasil were investigated. The temperature intervals of formation of isoparaffins from ethylene and propylene and aromatic hydrocarbons from mixed C-2-C-4 olefins and paraffins were found.