Non-spherical colloidal silica nanoparticle was prepared by a simple new method,and its particle size distribution and shape morphology were characterized by dynamic light scattering (DLS) and the Focus Ion Beam (FIB) system.This kind of novel colloidal silica particles can be well used in chemical mechanical polishing (CMP) of sapphire wafer surface.And the polishing test proves that non-spherical colloidal silica slurry shows much higher material removal rate (MRR) with higher coefficient of friction (COF)when compared to traditional large spherical colloidal silica slurry with particle size 80 nm by DLS.Besides,sapphire wafer polished by non-spherical abrasive also has a good surface roughness of 0.460 6 nm.Therefore,non-spherical colloidal silica has shown great potential in the CMP field because of its higher MRR and better surface roughness.