The I-V characteristics and the electrical switching behavior for a bulk glass system of the composition (80-x)% V2O5-(x)% SrO-20% FeO [15 <= x <= 40], have been investigated at different temperatures. The studied glasses are found to exhibit a current control led-negative resistance behavior of the threshold switching mode and the results are discussed in terms of the electrothermal model. It was concluded that the threshold voltage increased as SrO was gradually increased while it decreases when the temperature was increased. The activation energy for switching was found to decrease with the increase of SrO content. The field lowering coefficient 6 which was calculated experimentally appeared in agreement with that calculated from Poole-Frenkel equation beta(PF). (c) 2004 Elsevier B.V. All rights reserved.