Protein-imprinted soft-gel composite microspheres with magnetic susceptibility (MS-PIGMs) were prepared by inverse suspension polymerization, using Fe3O4 particles as magnetically susceptible component, acrylamide (AM) and N,N'-methylenebisacrylamide (BisAM) as polymeric matrix components, toluene as solvent, and bovine serum albumin (BSA) and lysozyme (Lyz) as templates, respectively. The surface morphology of MS-PIGMs was observed by environmental scanning electron microscope (ESEM) and scanning electron microscope (SEM). The effects of the kinds and amount of dispersants, stirring rate, the amount and adding methods of initiator, the amount of Fe3O4 and monomer concentration on particle morphology of MS-PIGMs, as well as the effects of crosslinking degree on swelling ratio and particle morphology in wet condition were investigated in detail. ESEM and SEM photographs showed that the resulting MS-PIGMs were all spheroid form and had large quantity of regularly distributed pores in wet condition, which close in dry condition, and the experimental results indicated that all the affecting factors had obvious effects on particle morphology of MS-PIGMs. (c) 2006 Wiley Periodicals, Inc.