A　zirconia　coated　alumina　nanocomposite　was　synthesized　by　the　one-step　alkoxide　hydrolyzing　method.　A　layer　of　very　uniform　nanocrystalline　zirconia　shell　with　its　thickness　about　4　similar　to　5nm　was　successfully　coated　onto　the　commercial　nano-alumina　particle.　The　thickness　of　the　zirconia　layer　can　be　controllable　by　adjusting　the　concentrations　of　zirconium　source　and　acetic　acid.　The　results　show　that　such　novel　core-shell　nanocomposite　powders　of　alumina-zirconia　can　be　helpful　to　inhibit　the　much　faster　growth　of　alumina　particles　and　show　the　uniform　surface　morphogenesis.　XRD,　TEM,　FESEM　and　EDS　were　used　for　the　structural　characterizations.