This paper presents a new porous silica microsphere packing for gel permeation chromatography (GPC).

The composite silica microsphere was obtained through the polymerization of urea and formaldehyde occurred in the silica sol that prepared from the hydrolyzation of tetraethyl orthosilicate.

The present invention is monodisperse silica coated hollow magnetic microsphere and its preparation process and belongs to the field of nanometer magnetic material technology.