Abstract: Sepharose-SPA Immunomagnetic Microspheres were prepared by means of inverse suspension embedding method. Product structure, particle size and magnetic properties were characterized and analyzed. The product particle size is about 5μm, with good dispersion and exhibits super-para-magnetism. SPA was coated on surface of Fe₃O₄ Magnetic Microspheres. In the experiment, IgG, which had specific adsorption action with SPA, was separated from Porcine Serum by Magnetic Microspheres. The experimental results indicate that the best adsorption rate of SPA Immunomagnetic Microspheres is 70.12% and it can be repeatedly used for 29 times.