The dispersion behavior of some oxides on the surface of SnO2 and the effects on the thermal stability of SnO2 have been studied. The results show that many oxides such as NiO, CuO, ZnO, Bi2O3, MoO3, Cr2O3 and Sb2O3 can disperse onto the surface of SnO2 by impregnation method or dry method-mixing a compound with the support thoroughly, followed by calcination at an appropriate temperature. The utmost dispersion capacities of these oxides on the surface of SnO2 are measured and they are all in good agreement with those estimated by a close-packed monolayer model. These oxides dispersed on the surface of SnO2 can retard the decrease in the specific surface areas of the samples and the increase in the crystallite size of SnO2 during calcination. In numerous effect factors, the surface coverage is a key factor. It is easy to stabilize the size of SnO2 grains to be 6 nm by this means, and the higher the valence of the cation of oxide, the stronger the stabilizing effects.