This paper presents several important topics in surface catalytic chemistry. Atom-resolved and nano-scale structures of TiO@sub x@ on TiO@sub 2@(110) and (001) surfaces have been visualized by STM and NC-AFM. The surfaces and the TiO@sub x@ structures were transformed to new surface structures in a complicated manner induced by heating and adsorption. Structure models are presented. Carboxylic acids were catalytically decomposed on TiO@sub 2@(110), and the reaction sites and reaction kinetics were characterized by in-situ STM observation. Nano-structures of Pt and Au on TiO@sub 2@(110) were produced by using Pt or Au precursor complexes in different ways. A unique clear-cut size regulation of the Pt particles was found. A new mechanism is presented. Very small Au particles with 0.7 nm height were successfully formed by UV irradiation of the Au-complex adsorbed surface or by UV irradiation of TiO@sub 2@(110) before deposition of the Au complex. Very small Au particles are remarkably active for low temperature CO oxidation. Atom-resolved and cluster structures of and around oxygen defects at CeO@sub 2@(111) surface have also been imaged by NC-AFM. The oxygen defects were mobile even at room temperature. The phenomenon was entirely different from that observed with the TiO@sub 2@ surface, which may be relevant to oxygen reservoir and oxidation activities of CeO@sub 2@ in automobile catalysts and oxidation catalysts. These surfaces are dynamic and reactive, depending on temperature and atmosphere, which may be relevant to the origin and mechanism of catalysis.