The book entitled, "Preparation, Characterization and Photocatalytic Activity of Metal Oxide Nanomaterials" is divided into four chapters. The first chapter deals with introduction of nanomaterials. Chapter second reveals the characterization of nanomaterials. The third chapter includes preparation & photocatalytic activity of Ag doped TiO2 nanomaterial. The fourth chapter deals with preparation of In doped TiO2 nanomaterials and studied its photocatalytic application.