Conventionally, heterogeneous catalysts are mainly focused on the materials with large surface area because the heterogenenous catalysis occurs on the surface. However, some catalysts even with small surface area (< 10 m²/g) are still catalytically active in oxidations, which really extend the searching for novel heterogenenous catalysts. Generally, these materials with small surface area are considered as catalytically inactive catalysts for a long time. This review shows that a series of metal oxides such as La-Sr-Cu-O, V-Zr-O, Cu-Bi-V-O, Cu₂(OH)PO₄, and Fe-Mg-O exhibit both high activities in the oxidations of smaller molecules such as phenol hydroxylation, benzene hydroxylation, styrene epoxidation, and high activity in the oxidations of larger molecules such as hydroxylation of 2,3,6-trimethylphenol. Furthermore, Cu₂(OH)PO₄ catalyst is very active for olefins epoxidation by molecular oxygen, which is important for use of cheap oxygen source for industrial oxidation process. The characterization of the catalysts by ESR proposed that the radicals such as hydroxyl radicals, hydroperoxyl radicals and phenoxy radicals are important for the oxidations, which are distinguishable from the oxidation over TS-1 catalyst.