The NaF-CaF_2 system has been studied by molecular dynamics simulation.The paircorrelation functions between cations and anions and the bond angle distributions ofcation and anion triplets have been obtained.The bridging and complexing in the systemare discussed based on the pair correlation functions and bond angle distributions.Theresults simulated show that the F~- ions around a Ca~(2+)ion do not form tetrahedroncoordination,so some of small complexing clusters such as CaF_4~(2-)are hardly found.Apossible structure of F~- ions around Ca~(2+)ions is that three Ca~(2+)ions constitute anequilateral triangle through three Ca-F-Ca bridges and two F~- ions are located overand under the center of the right triangle,respectively.Meanwhile,on the outside of thetriangle,every Ca~(2+)ion has other two F~- ions as its neighbors. The NaF-CaF 2 system has been studied by molecular dynamics simulation. The paircorrelation functions between cations and anions and the bond angle distributions of cation and anion triplets have been obtained. Bridging and complexing in the systemare discussed based on the pair correlation functions and bond angles distributions.The results simulated show that the F ~ - ions around a Ca ~ (2+) ion do not form tetrahedroncoordination, so some of small complexing clusters such as CaF_4 ~ (2-) are hardly found. Around Ca ~ (2+) ions are that three Ca ~ (2+) ions constitute anequilateral triangle through three Ca-F-Ca bridges and two F ~ - ions are located overand under the center of the right triangle, respectively. on the outside of thetriangle, every Ca ~ (2+) ion has other two F ~ - ions as its neighbors.