As the abundant reactive groups on the molecular chain of chitin and chitosan
their graft copolymeric derivant can be gained via reacting of macromolecular free radical initiated on the chain of them with vinyl monomer or by coupling of them with other polymer chain. The excellent additional property can be gained by graft copolymerization of chitin and chitosan and their application fields call be enlarged. In this paper
the progress and mechanism of graft copolymerization of chitin and chitosan and the property of the products are introduced.