Giant dielectric permittivity (epsilon) with low loss tangent (tan) was reported in (In+Nb) co-doped TiO2 ceramics. Either of electron-pinned defect-dipole or internal barrier layer capacitor model was proposed to be the origin of this high dielectric performance. Here, we proposed an effectively alternative route for designing low-tan in co-doped TiO2 ceramics by creating a resistive outer surface layer. A pure rutile-TiO2 phase with a dense microstructure and homogeneous dispersion of dopants was achieved in (In+Nb) co-doped TiO2 ceramics prepared by a simple sol-gel method. Two giant dielectric responses were observed in low- and high-frequency ranges, corresponding to extremely high epsilon approximate to 10(6)-10(7) and large epsilon approximate to 10(4)-10(5), respectively. After annealing in air, a low-frequency dielectric response disappeared and could be restored by removing the outer surface of the annealed sample, indicating the dominant electrode effect in the initial sample. Annealing can cause improved dielectric properties with a temperature- and frequency-independent epsilon value of approximate to 1.9x10(4) and cause a decrease in tan from 0.1 to 0.035. High dielectric performance in (In0.5Nb0.5)(x)Ti1-xO2 ceramics can be achieved by eliminating the electrode effect and forming a resistive outer surface layer.