In this study, the dually imprinted alginate polymer microspheres are prepared using proteins and o/w emulsion drops as dual templates with different structure and composition such as the content of hydroxylethyl cellulose (HEC), crosslinking degree, and porous size, etc. The rebinding tests are carried on egg white albumin (EA) protein imprinted alginate polymer microspheres with interpenetrating networks (IPNs) under various conditions like ionic strength, temperature, protein concentration, and pH value. Results showed that the IPNs with alginate and HEC by covalent bond influence the rigidity and swelling properties. Porous structure formed by introducing emulsion drops into alginate hydrogel has effect on the permeability and specific surface area of the polymer microspheres. The variation rule of rebinding behavior according to different HEC content and pore diameters reveals macromolecular imprinting effect to be different with pure pore creating effect compared with the emulsion imprinting effect. Moreover, the macromolecular and emulsion dually imprinting-rebinding tests verify the coexisting macromolecular imprinting effect and pore creating effect of emulsion imprinting. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 3516-3526, 2010