Intermacromolecular complexes of poly (acrylic acid) (PAA) with poly (ethylene oxide) (PEO), poly (ethylene imine) (PEI) and poly (vinyl pyrrolidon) (PVP) were prepared. The stability constants and thermodynamic parameters (e.g. Delta H-0 and Delta S-0) of these complexes were determined at several temperatures. The enthalpy and entropy changes of the systems with temperature have been interpreted in terms of various mode of interaction between the components and compared with each other.