The thermostability of ZrO2 can be improved by dispersing a layer of an active component onto its surface in advance. The research results of seven kinds of catalysts (ZrO2-supported MoO3, WO3, CuO, SO42-, NiO, FeSO4 and Fe2O3) show that the surface areas of the samples prepared by impregnating Zr(OH)(4) with the active components and then calcining at high temperature are much larger than those of the samples prepared with an ordinary method, namely, impregnating ZrO2 calcined at high temperature. The surface areas of the ZrO2-supported catalysts obtained in this way are several times that of pure ZrO2 calcined at the same temperature. The characteristic results show : (1) the active components are dispersed on the surface of ZrO2 as monolayer; (2) there is a good corresponding relationship between the surface coverage and the surface area of the sample; (3) as the loading of an active component comes up to its utmost dispersion capacity, the surface area of the sample will be the largest. The mechanism responsible for these phenomena has been discussed.