Polyoxometalates (POMs) are molecular metal oxides composed of transition metals in their highes oxidation states (Mo,W,V,Nb,Ta). The high solubility and low specific surface area of pure inorganic POMs limi its practical applications in polar solvents. Due to the widespread applications of organic?inorganic hybrid POMs and immobilized POMs in the field of catalysis, energy conversion, storage and magnetism have attracted considerable attention.The design and synthesis of transition metal/Lanthanide modified organic?inorganic polyoxometalates and immobilized polyoxometalates composites are reviewed,and the practical applications of POMs with novel structures are summarized and outlooked.