Abstract: The surface of gelatin hydrogels behaves as a strongly hydrophobic and low-energy surface. The Surface free energy of gelatin hydrogels was estimated by measuring the contact angle of some reference liquids on the gelatin hydrogels.The surfactants,especially the nonionic surfactants, dissolved in the hydrogels,increases the surface free energy and improves pronouncedly the wettability of gelatiin hydrogels. The results are interpreted in terms of adsorption and orientation of molecules on the surface, as well as by the existence of the non-polar network in gelatin hydrogels.