The magnetically photocatalytic particles prepared have a core-shell structure of three layers coating magnetite core particles with silica and titania by the hydrolysis of tetraethoxysilane and titanium tetraisopropoxide, respectively. The thicknesses of silica and titania layers were controlled by changing the concentrations of two alkoixides used. The coated photocatalytic particles were heated at 773 K under the nitrogen or hydrogen atmosphere in the tube furnace. By the heating process, the surface titania layer of photocatalytic particles varied to titanium dioxide, of an anatase type, and the magnetism of particles increased. It was found that, from the decomposition experiments of the rhodamine B, the prepared photocatalytic particles had good photocatalytic activities and that they can be easily separated by magnetism. Furthermore, the result of the decomposition experiments revealed that the thicknesses of silica and titanium layers are mainly influenced by the photocatalytic activity.