Catalytic oxidation of m-xylene was carried out over the copper oxide catalyst loaded on SiO2 300 m2/g. The various techniques were used to characterize the catalysts x-ray diffraction, TPRH2, N2 adsorption-desorption, scanning electron microscopy (SEM), tranmission electron microscopy (TEM) and CO pulse chemisorptions. The results indicate that the impregnated solution concentration exerts an influence on the catalytic activity. The active nano particle’s diameter of the sample 1%CuO/SiO2 impregnated by the dilute solution is around 3 nm (by the SEM, TEM and CO pulse chemisorptions methods) and the metal dispersion is about 40%. This catalyst has the total conversion of m-xylene at 260o C. By the method TPR-H2 we can found that the catalytic sites of the copper oxide/SiO2 are CuO, Cu2O and spinel Cu[Si]2O4.