Ultra-puremesoporoussilicamicrosphereswithgoodmonodispersityweresynthesizedintwosteps:nanometer-sizedsilicasolwasproducedbythesol-gelprocess,thenmicrometer-sizedsilicamicrospheresweresynthesizedbypolymerization-inducedcolloidaggregationofthesilicasol.Thetotalmetalcontentofthemicrosphereswasextremelylow,whicheliminatedthetailingofchromatographicpeaksbychelatingreagents.Theporestructureofthesilicamicrospherescouldbecontrolledbyalteringthesol-gelconditions.Thesilicamicrosphereparticlesizecouldbeadjustedbyusingdifferentpolymerizationinducedcolloidaggregationconditions.