Abstract: The Pt-Sn catalysts with the -Al₂O₃ support have been used as the cata lyst for the dehydrogenation of long chain n-paraffins to produce mono olefins. It had been found in our investigation that the catalyst prepared by a new method to improve the interaction between Pt and Sn has higher sta bilities than those by conventional method with the same composition of Pt and Sn. In order to characterizing the surface structures and the reaction properties of these catalysts, the characteristics of two Pt-Sn catalysts pre pared by different methods were studied by means of the M(ssbauer spe ctroscopy, TPD of H₂, and reaction kinetics study of cyclohexane dehydroge nation. These experiments give the evidence that the interaction between Pt and Sn may be improved, if the catalyst is prepared by complex method. The stabilities of these catalysts are obviously enhanced, as well as the ene rgy of activation of dehydrogenation are much higher than the catalyst pre pared with the conventional method. These results show that this type of catalysts will be superior than the conventional commercial Pt-Sn catalysts if they are used in the process of mono-olefin production.