Bi, Y, and Al-doped antimonic acids with the empirical formula (1-x)Sb2O5·xM2O3·nH2O (M =Al, Bi and Y; 0 ≤ x ≤ 1) have been prepared by the direct reaction of an aqueous H2O2 solution with metal alkoxides. The electrical properties have been investigated by ac and dc conductivity measurements using a polycrystalline compactdisc as a sample, in connection with the water adsorption behavior. The (1-x)Sb2O5·xM2O3·nH2O (M = Bi and Y) materials exhibit a solid solution of cubic antimonic acid (Sb2O5·nH2O) with Bi2O3 and Y2O3 in the range of x = 0 – 0.1, and the ionic transference numbers of the materials are all over 0.98. The proton conductivity of (1-x)Sb2O5·xM2O3·nH2O (M = Bi and Y; x = 0.1) at room temperature increases to over 10-3 Scm-1 with an increase in the relative humidity. The conductivity is closely affected by the water adsorption behavior, which seems to be related to the introduction of oxygen vacancies.