Glasses of the series 0.65((1+x)Ag2OYB2O3 (1-Y)P2O5)0.35AgI (0 less-than-or-equal-to x less-than-or-equal-to 0.6 and 0 less-than-or-equal-to y less-than-or-equal-to 0.2) have been prepared. Their glass transformation temperature, T(g), electrical conductivity, sigma, and conduction activation energy, E(sigma) and preexponential factor, sigma0, have been evaluated. The substitution of B2O3 to P2O5 has been found to be useful in making both T(g) and sigma to increase. The results have been interpreted on the basis of a structure composed of AgI microdomains in a phosphate or borophosphate matrix and on the basis of the diffusion path model for ionic conduction.