The structure and ion mobility in glasses in the PbF 2 –BiF 3 –ZrF 4 ternary systems have been studied by Raman and 19 F NMR spectroscopy. Raman spectra of glasses of compositions with concentration ZrF 4 >45% remain typical for fluorozirconate glasses and zirconium complex fluorides. The correlation between the vibrational data and the n(F)/n(Zr+Bi) ratio in glasses is identified. The glass network in the BiF 3 –PbF 2 –ZrF 4 system is formed according to the zirconium complex fluorides structural regularities. The Zr nearest surrounding and the glass network polymerization degree depend on the nF/n(Zr+Bi) ratio. One can affirm that the coordination number of Zr atom is equal to 7–8. BiF 3 completely loses its individual crystal geometry in the structure of glasses under study: it serves as an ‘intermediate’, providing the glass stability at ZrF 4 concentrations up to 40mol%. For the investigated glasses n(F)/n(Zr+Bi) ratio is between 5 and 4. Found that with temperature increasing (150→550K) in the fluorine subsystem of the glasses the transition is observed from a rigid lattice to diffusion through an intermediate phase associated with an appearance of local motions of zirconium fluorine-containing groups that form the glass network. Examined the correlation between the temperature at which this transition occurs, and the concentration of fluoride in the glass composition is included.