The　phase　conversion　of　Al2O3　during　high-energy　ball　milling　was　investigated.　After　20h　milling,　amorphous　and　AlN　were　observed　in　powders,　these　were　not　reported　previously.　The　crystal　structure　of　AlN　gained　during　ball　milling　is　cubic,　differs　from　that　of　the　regular　hexagonal　AlN　synthesized　with　carbothermal　reduction.　AlON　phase　forms　by　the　reaction　of　cubic　AlN　and　gamma-Al2O3　after　annealing　in　N-2　atmosphere　at　the　temperature　above　500　degrees　C.　The　formation　of　AlON　phase　decreases　the　commencing　temperature　of　AlN.