The process which take place with help of catalyst is called catalysis. Type of catalysis depends on the nature of catalyst such as homogenous catalysis, heterogenous catalysis, enzymatic catalysis and nano-catalysis. A variety of products like medicines, fine chemicals, polymers, fibers, fuels, lubricants, and a myriad of other value added products essential to humans, is feasible only due to presence to catalyst. Nano catalysis has long become a vital part of Nano science. Nanoparticle can substitute conventional material and serve as active and stable heterogeneous catalysts or as support material for various catalytic groups. Due to their small sizes, catalytic active nanoparticles have higher surface area and increased exposed active sites, and thereby improved contact areas with reactants, akin to those of homogeneous catalytic systems. The application of nano-catalyst is reported in various field such as biodiesel production, drug delivery, and photo catalysis. Coupling reaction, hydrogenation reaction, nano toxicology, solar cell, waste water treatment etc.