The conductivity of samples based on Sm2W3O12 obtained by using homogeneous (solid solutions Sm2 –xМxW3O12 – 0.5x, where М = Ca, Zn) and heterogeneous (composites (1 – φ)Sm2W3O12–φWO3) doping is studied. The introduction of 1 mol % М2+ into the Sm3+ sublattice increases the conductivity by a factor 1.5–2; the introduction of a larger amount of М2+ produces multiphase samples. The heterogeneous doping of the oxygen-ion conductor Sm2W3O12 by tungsten oxide increases the ionic conductivity more than 10 times.