A　lanthanum-cerium-based　abrasive　composed　of　CeO2,　LaOF,　and　LaF3　was　commercially　obtained.　The　effect　of　sodium　hexametaphosphate　(SHMP)　on　powder　dispersion　behavior　was　systematically　investigated　using　the　combined　techniques　of　liquid　contact　angle,　turbidity,　zeta　potential　(ZP),　scanning　electron　microscopy　(SEM),　powder　X-ray　diffraction　(XRD)　combined　with　Rietveld　refinements,　X-ray　photoelectron　spectroscopy　(XPS),　and　polishing　tests.　The　results　indicated　that　the　addition　of　0.5　wt.%　SHMP　dispersant　to　the　5　wt.%　lanthanum-cerium-based　slurry　produced　the　most　stable　suspension　with　a　high　turbidity　of　2715　NTU　and　a　low　wetting　angle　of　45　degrees.　The　as-obtained　slurry　displayed　good　surface　polishing　quality　for　K9　glass,　with　low　surface　roughness　(Ra)　of　0.642　and　0.515　nm　(in　the　range　of　979　x　979　mu　m2)　at　pH　=　6　and　11,　respectively,　which　corresponds　to　the　fact　that　it　has　local　maximum　absolute　values　of　ZP　at　these　two　pH　values.　SEM　images　demonstrated　that　after　appropriate　grafting　of　SHMP,　the　particle　aggregation　was　reduced　and　the　slurry＇s　dispersion　stability　was　improved.　In　addition,　the　dispersion　mechanism　was　explained　based　on　the　principle　of　complexation　reaction,　which　reveals　that　the　dispersant　SHMP　can　increase　the　interparticle　steric　hindrance　and　electrostatic　repulsions.　In　an　acidic　environment,　steric　hindrance　dominates,　while　electrostatic　repulsion　prevails　under　alkaline　conditions.　As　expected,　this　polishing　slurry　may　find　potential　applications　in　manufacturing　optical　devices　and　integrated　circuits.