PS/SnO_2 microspheres with single and multi SnO_2 adsorption layers are prepared by layer-by-layer (LBL) assembly technique. Morphology of obtained microspheres are observed by TEM and FESEM,chemical structure and constitution of PS/SnO_2 are analyzed by using FT-IR and TGA. Influences of pH,disperse solution and absorbed layers on preparation of PS/SnO_2 core-shell microspheres are investigated and optimized preparation conditions are obtained.