The behavior of La/Al2O3 + ZSM catalysts has been studied in the process of the hydrogen-free conversion of tetradecane. The structure and state of active centers of catalysts have been investigated using a combination of physicochemical and instrumental methods (TPD of ammonia, IR spectroscopy, electron microscopy). It was found that the catalysts are characterized by the presence of acid (Bronsted and Lewis) sites and M-0 and M (n+) metal centers. Lanthanum in different oxidation states can be included in the acid sites. The degree of tetradecane conversion and the product composition are determined by the SiO2/Al2O3 ratio of the zeolite and the conditions of the process. The mechanism of the cracking and transformations of tetradecane on La/Al2O3 + ZSM catalysts is discussed.