The temperature-concentration dependences of the electrical conductivity and the activation energy for electrical conduction of glasses in the Na ₂O-B₂O₃ and Na₂O₄-2PbO · B₂O₃ systems are studied. The investigation into the nature of the electrical conduction in these glasses reveals that the contribution from the electronic component (10^-3%) of the conductivity is within the sensitivity of the Liang Wagner technique. A considerable alkali conductivity is observed upon introduction of more than ∼12 mol % Na₂O. The true transport number of sodium η _Na+ is as large as unity at [Na₂O] ≒ 15 mol %. It is shown that the observed temperature-concentration dependences of the electrical and transport properties are governed by the ratio between the concentrations of polar and nonpolar structural-chemical units of the Na ⁺[BO_4/2]^-, Na⁺[O^-BO _2/2] ⇒ Na⁺[O^-BO_2/2], Pb _1/2 ²⁺[BO_4/2]^-, Pb_1/2 ²⁺[BO_2/2], and [BO_3/2] types.