With molecular dynamics study,we investigate microstructure of liquid Al₂O₃ at 2663 K and 2223 K.The first and second nearest-neighbor distances are in good agreement with results of Ansell et al.Analysis on coordination numbers and angle-distribution functions show that the microstructure of liquid aluminum oxide mostly consists of three-fold coordination of oxygen,four-fold and five-fold coordination of aluminum.Evidence of liquid-liquid phase transition due to separation of high and low coordinate species is not found.