Abstract: A fluorescent coordination complex of Eu(dbm)₃ phen was synthesized by the reaction among dibenzoyl methane, 1,10-phenanthroline and europium chloride, and was embedded into the SiO₂ microsphere prepared by the surface protected water-etching, to obtain the compound microspheres of Eu(dbm)₃phen/SiO₂. To overcome the leakage of the microsphere, a layer of KH570 (ca. 10 nm) was covered onto the surface of microspheres, to form core-shell structure. And in addition, to have epoxy groups attached to the microspheres, polymerization with GMA was carried out. The epoxy rings were opened by reaction with ethylene diamine, thus to have aminogroups attached on the surface of microspheres, to keep 72% of its original fluorescence intensity, and to have convenience in linking with antibody. The structure and properties of the above mentioned microsphere material were studied thoroughly by DLS, SEM and so on. It was shown that this material is suitable to be used for biolabelling in fluoro-immuno-assay.