The method presents obtaining hydrosoluble graft copolymer of complicated structure based on сhitosan, acrylamide (AM), sodium 2-acrylamido-2-methylpropane sulfonic (АМPS-Na) in order to obtain fl ocсulant which is resistant to salt of transition metals and heat temperature, and in order to use it as a reagent for oil production processes. The obvious advantages of this copolymer can be attributed to its biodegradation due to inclusion of a biopolymer into the composition of the copolymer, which is important for the preservation of ecology, and effi ciency of its synthetic analogues. The graft copolymerization acrylamide and sodium 2-acrylamido-2-methylpropane sulfonic onto active sites of chitosan has been performed under condition of high concentration monomers in nitrogen atmosphere using combined initiator system of complex composition under the following order monomers [АА]>[АМПС-Na]. Kinetic study of graft copolymerization has been carried out using thermometry methods. Attempts have been made to describe mathematically the reaction of graft monomers АM and АМPS-Na onto chitosan. The IR spectra analysis of copolymers has been carried out. The study of reaction rate and molecular characteristics of synthesized copolymers has been conducted under changing concentration of chitosan, monomers, ratio components of the initiator system and reaction temperature during synthesis. It has been determined that the averaged energy activation of copolymerization reaction was in the range of reaction temperature 10–25°С. Molecular composition and proposed structure of the grafted copolymers have been determined by the results of viscosity and sedimentation analysis. The results of this study allow to obtain grafted copolymers with specifi ed properties and structure to use them in such areas as sewage and industrial water treatment and mineral industry.