Ionic liquids are organic salts which are liquid near ambient temperatures. They are non-volatile

highly polar solvents that dissolve several organic

inorganic and metal organic compounds. Although there is an increasing number of reports dealing with the application of ionic liquids as solvents for organic synthesis

their use in polymer synthesis is still limited. In the last few years

however

it has been shown that ionic liquids can be advantageously used also for polymer synthesis. In radical polymerization the increase of Kp/Kt ratio for polymerizations conducted in ionic liquids has been observed. Specially

application of ionic liquids as solvents for Atom Transfer Radical Polymerization facilitates separation of the polymer from residual catalyst and reduces the extent of side-reactions. This paper has mainly discussed the principle and feature of atom transfer radical polymerization as well as the applications of ionic liquids in the atom transfer radical polymerization. It has also introduced the previous works and the development prospect of ATRP.