The interaction between poly(sodium phosphate) and p-aminobenzoic acid: hydrochloride was investigated by conductometry, viscometry, spectrometry and gravimetry. It was found that the complex stoichiometry deviates from unity and the composition of the complex was independent of the order of addition. Dissolution of complex was achieved by organic solvents. After dissolution in organic solvent, complex was titrated in the presence and absence of bivalent cupric ions under condition of ionic strength. (C) 2001 Elsevier Science Ltd. All rights reserved.