This paper reviews a series of novel water-tolerant polyoxometalate-containing composite photocatalysts such as amine-functionalized mesoporous silica/anatase titania impregnated with transition metal substituted polyoxometalates, bimodal porous polyoxotungstate-anatase TiO2 nanocomposites, Fe-polytungstate-silica-structured fabrics, monovacant Keggin unit-silica/titania composite films, and highly ordered macroporous monovacant Keggin unit-titania composite films, including their design, preparation, optical absorption property, surface physico-chemical property, morphology, and heterogeneous photocatalytic behaviors. Emphases are addressed on the efficient photocatalytic activity of as-prepared solid polyoxometalates in the near UV- and/or visible-light region and easier recovery of the catalyst from the reaction system. (c) 2006 Elsevier B.V. All rights reserved.