Metal clusters have been employed as catalysts by nature in form of enzymes ever since the life existed on earth. Also the metal clusters are unique example of the nano materials which have been successfully used by chemical industry as catalysts. Metal clusters range from two atom aggregates to thousands of atoms in a cluster with wide variety in sizes structures and properties. Metals have generally various oxidation states and thus are good catalysts. Synthesis of structurally uniform and simple metal clusters on crystaline solid supports gives us an opportunity for incisive characterization using complementary techniques such as EXAFS, TEM, IR, Mass Spectrometery etc. Moreover the systamatic variation of size and structure of cluster on a given support can facilitate correlation between structure and catalytic performance. Investigation of metal clusters in simple inorganic compounds can help us understand their role in enzymes.