Preliminary tests on the reaction for formaldehyde production from metoxi methane (DME) using a Mo/SnO2 catalyst have indicated the necessity of highly active systems. Dispersed species of Mo seem to be the most effective for this reaction which may be favored by the use of a support of high specific area. Therefore the influence of the synthesis parameters on the physicochemical properties of the SnO2 has been studied in this work. This oxide has been prepared by three different methods: by the oxidation of Sn0 using HNO3, by the reaction of Sn+4 with NH4OH, and by the reaction of Sn+4 with dodecylamine. Variations on the way of mixing the solutions, on the time and the temperature of the reaction, and on the heating rate of the calcinations step have been carried out. These samples have been characterized by N2 adsorption for measurements of specific area and pore size distributions, X-ray diffraction and UV-visible diffuse reflectance spectroscopy. The results have shown that all samples are mesoporous even though they have exhibited distinct values of specific area, crystal size and HOMO-LUMO gap energy. The reaction of Sn+4 with NH4OH has presented the greatest sensitivity to the synthesis parameters, and it has provided samples with the highest specific area values. However the samples prepared by the oxidation of Sn0 using HNO3 have not been influenced. The results have also indicated that the temperature and the reaction time seem to be the most important parameters.