Тhe interaction of polyacrylamide cross-linked by N, N ‘-metylenebisakrylamide (PAAm) with water vapor, water and water solutions of NaCl, Na2SO4, NH4Cl, (NH4)2SO4 and sucrose of different concentration еxperimentaly has been studyed. Dependence of degree of swelling of polyacrylamide gel from activity of water is established. Kinetic dependences of change of degree of swelling of PAAm granules in solutions of sucrose of different concentration are received. It is shown that at identical activity of water cross-linked polyacrylamide differently swells in solutions of different substances. The possible reasons of such behaviour are analysed. Key words: polyacrylamide gel, swelling, kinetics.