Abstract: Coulomb interaction, polarization effect and Van der Waals interaction play a significant role,and lead to the energetic asymmetry in the LnCl₃,/MCl molten salts. The negative deviation from idea solution behavior sharply increases with the mixture from LiCl to CsCl, and the short-rang maximun ordering was observed at x_LnCl≈ 0.2 from KCl to CsCl. Modified quasi-chemical model is a good approximation to describe the ordering properties. However, it is more reasonable to develop new thermodynamic model, considering the interaction between next closed-neighbor particles and interaction between unlike ion particles.