The composite particles of mSiO₂/CeO₂(330-340 nm in size) were prepared by applying CeO₂ nanoparticles coating (15-20 nm in thickness) on core material of mesoporous silica (mSiO₂, ca. 300 nm in size) with radial mesochannels (ca. 2.6 nm in pore size). The prepared composite particles were characterized by transmission electron microscopy, field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and nitrogen adsorption-desorption analysis. The results show that the oxidized silicon wafer substrates was polished comparatively with when taking mSiO₂/CeO₂ composite particles or sSiO₂/CeO₂ composite particles(solid silica core) as polishing paste, the polished pre-oxidized silicon wafer presented had a lower root-mean-square roughness(RMS=0.267 nm) and a higher material removal rate(MRR=45 nm/min) for the former paste, in the contrast, than those of the sSiO₂/CeO₂ composite particles with solid silica cores(RMS=0.309 nm and MRR=24 nm/min for the later one. Furthermore, the mSiO₂/CeO₂ composite particles may be beneficial were attributed to the elimination of mechanical damages (such as scratches) on the wafer surface. The very structure of silica core of mSiO₂/CeO₂ composite particles presented obvious effects for their polishing characteristics.