The water sorption of the films of polyacrylamide (PAA), gellan gum, agarose and PAA-gellan, PAA-agarose mixtures of different compositions was studied. The chemical potentials of water ∆µ1, polymer component ∆µ2, the averageGibbs energy of interaction of polymers and mixtures with water ∆gm, the average Gibbs mixing energy ∆gx, enthalpy ∆hx and entropy ∆sx of PAA and polysaccharides have been determined. It is determined that the Gibbs mixing energy of PAA with polysaccharides are different signs in the concentration range. The entropy of the mixing system PAA-agarose is negative for all compositions. In the system PAA - gellan the entropy is negative for mixtures enriched with PAA. The mixture of polyacrylamide with polysaccharides in the entire composition range is accompanied by an exothermic thermal effect.