In the present work the electrical properties of (1 - x)Ce_0.8Gd_0.2O_{2 - δ} + xTiO₂ (x = 0-0.06) synthesized by the standard ceramic technology were investigated, in a wide range of oxygen partial pressures (0.21-10^{- 20}atm at 900 °C) and temperatures (600-900 °C), both in air and H₂ + 3%H₂O atmosphere. It was found, that only the introduction of above 1 mol% TiO₂ decreases the sintering temperature of Ce_0.8Gd_0.2O_{2 - δ}. The values of total electrical conductivity do not change significantly with the content of the sintering aid up to 3 mol%, while the activation energy of total conductivity in air decreases considerably with the introduction of TiO₂ into Ce_0.8Gd_0.2O_{2 - δ} from 87 to 67 kJ/mol; however, it is independent of x up to 0.03. The dependence of the total conductivity on the oxygen partial pressure is characterized by three regions. In the intermediate region (10^{- 10}-10^{- 14}) the conductivity behavior is described according to the oxygen vacancy model. The n-type conductivity region curve of Ce_0.8Gd_0.2O_{2 - δ} is fitted to a -1/5 slope. The increase of TiO₂ content leads to the slope increase at - 1/6, - 1/8 and - 1/9 for 1, 2 and 3 mol% TiO₂, respectively, due to the trapping of electrons by Ti⁴⁺. 1 mol% doping increases the electrolytic region of Ce_0.8Gd_0.2O_{2 - δ} from 10^{- 10} to 10^{- 13}atm. Finally, the optimal content of TiO₂ from the viewpoint of sintering and electrical properties was found to be 2 mol%.