The structure and ionic conduction of glasses in system LiF-LiCI-B2O3, especially the role of F- ion in network of glasses and the influence of F-, Cl-, Li+ ions on conductivity have been studied by B-NMR and infrared spectra. For glasses in system LiF-LiCl-B2O3, the boron changes from triangular [BO3] to tetrahedron [BO3F] configuration with increasing LiF content, and F- ion participates in network formation. Therefore the network of glasees expands layer into space, and the glasses form three-dimensional network structure containing [BO3F] unit. The Cl- ion exists in network in a state separated from network and plays the role of loosening network, so that it is effective for conductivity. The Li+ ion is the conductive phase, it gives the major contribution to conductivity. The ionic conductivity of glasses in this system increases with increasing LiF and LiCl content, and is 6.12×10-4Ω-1·cm-1 at 300℃.