Glasses based on vanadium oxyfluoride have been synthesized and characterized. Glass formation have been investigated in the V2O5-BaF2-RF ternary and quaternary systems, where RF: LiF, NaF and mixed NaF-LiF. Density, molar volume, characteristic temperatures, average thermal expansion coefficient, alpha, and specific heat, C-p, have been measured. From DSC results the activation energy, E-g, at the glass-transition temperature T-g, is calculated for the prepared glasses. Density increased while molar volume decreased as alkali fluoride content increased. The glass-transition temperature, T-g, decreased by increase of RF while thermal expansion, alpha, and specific heat, C-p near T-g increased. The interatomic distance between the ions were calculated and then the stretching force constant, F. (C) 2007 Elsevier B.V. All rights reserved.