The coordination and bond properties of aluminium and silicon ions were discussed by means of molecular dynamics simulation. By combining KA and MATSUMIYA potentials, the results of simulations agree better with the experiments. Trend of coordination and bond properties changing along with the increasing content Al 2O 3 from 0 to 100% (mole fraction) was obtained. Average bond lengths of Si O in these simulations are within the range of 1.60 ～ 1.63?? and become smaller from 1.63?? in sample 0 to 1.60?? in sample 9 along with increasing content of Al 2O 3. Average bond lengths of Al O are within the range from 1.77?? in sample 1 to 1.86?? in sample 10. By analyzing the relation of CN(T) and CNSi(T) with Si/(Si+Al), it is found that Al mainly locates on the tetrahedral sites which neighbor the Si tetrahedra but avoid the Al tetrahedra while alumina content is low. Whereas when Si/(Si+Al)< 0.5, Al octahedral units appeared and became predominant gradually. Meanwhile, Al avoidance principle can only be maintained at low alumina content. With increasing alumina, this principle would be broken gradually. The coordination and bond properties of aluminum and silicon ions were discussed by means of molecular dynamics simulation. By combining KA and MATSUMIYA potentials, the results of simulations agree better with the experiments. Trend of coordination and bond properties changing along with the increasing content Al 2O 3 from 0 to 100% (mole fraction) was obtained. Average bond lengths of Si O in these simulations are within the range of 1.60 ~ 1.63 ?? and become smaller from 1.63 ?? in sample 0 to 1.60 ?? in sample 9 along with increasing content of Al 2 O 3 Average bond lengths of Al O are within the range from 1.77 in sample 1 to 1.86 in sample 10. By the relation of CN (T) and CNSi (T) with Si / (Si + Al), it is found that Al mainly locates on the tetrahedral sites which neighbor the Si tetrahedra but avoid the Al tetrahedra while alumina content is low. Whereas when Si / (Si + Al) <0.5, Al octahedral units appeared and became predominant gradu ally. Meanwhile, Al avoidance principle can only be maintained at low alumina content. With increasing alumina, this principle would be broken generally.