The adsorption of certain biomolecules from aqueous solution on two polymeric adsorbents namely Amberlite XAD-4 and XAD-7 was studied in order to assess the effect of solute chemical nature. Adsorption affinity quantified as the slope of the linear region of the isotherm correlates well with important molecular properties of the solutes such as hydrophobicity, van der Waals interaction parameter and molecular connectivity. A novel correlating parameter could be derived from the molecular connectivity which provides topological description in terms of branching index and fundamental treatment of the molecular structure based on a valence weighted graph of the structural formula of a compound. Moreover, study reveals interplay between different driving forces in adsorption of biomolecules on polymeric resin. (C) 2007 Elsevier Ltd. All rights reserved.