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In the present investigation we report the synthesis of a series of transparent glasses of composition 20Li 2 O 20PbO 45B 2 O 3 (15− x ) P 2 O 5 : x V 2 O 5 with eight values of x ranging from 0 to 2.5 mol%, and their characterization. X-ray diffraction (XRD) spectra reflected the amorphous nature of the glasses. Optical absorption, electron paramagnetic resonance (EPR) spectra and FTIR study of vanadyl ions in the present glass network have been analyzed. The optical absorption and EPR investigations have revealed that vanadium ions do exist in both V 4+ and V 5+ states and the redox ratio (V 4+ /V 5+ ) is observed to increase with the increase in concentration of V 2 O 5 . Dielectric properties viz., dielectric constant ε ′( ω ), loss tan δ , electrical moduli M ′( ω ), M ″( ω ), a.c. conductivity σ ac over an extensive scale of frequency and temperature have been investigated as a function of V 2 O 5 concentration. The dispersion of dielectric constant ε ′( ω ) with temperature has been interpreted by space charge polarization model. The dielectric loss and electrical moduli variation with frequency and temperature exhibited relaxation effects. These effects are ascribed to V 4+ ions. The a.c. conductivity of the prepared glasses is perceived to escalate with the hike in V 2 O 5 concentration whereas the activation energy for conduction exhibits a reverse trend. The conductivity mechanism is explained on the basis of polaronic transfer between V 4+ and V 5+ ions. The low temperature a.c. conductivity mechanism is elucidated by the quantum mechanical tunneling model. The growth in the values of dielectric parameters with raise in the concentration of V 2 O 5 is due to V 4+ ions which act as modifiers. The investigation of these results has indicated that at higher concentrations of V 2 O 5 , the VO 2+ ions in the glasses were present in octahedral sites with tetragonal compression and belong to C 4v symmetry. [ABSTRACT FROM AUTHOR]