The electrical conductivity, glass transition temperature Tg and density of lithium sulfoborosilicate glasses have been studied in two different series. An enhancement in the conductivity has been observed with addition of Li2SO4, which has been attributed to the incorporation Of SO4 tetrahedra in the macromolecular network. The reduction in Tg and density has been observed with increase in the Li2SO4 content in the glass. An attempt has been made to correlate the electrical conductivity with the results of Tg and density obtained on addition of Li2SO4. There is an expansion of the network with addition of Li2SO4 which reduces the rigidity of the glass matrix. This is supported by the lowering of Tg and density obtained in the glasses. The lower values of Tg and density of the glass are desirable to obtain enhancement in the conductivity. (c) 2006 Elsevier B.V. All rights reserved.