SrTi1-xCoxO3 (0.2≥x≥0) polycrystalline samples were prepared by solid-state reaction. X-ray diffraction (XRD) analysis shown the perovskite type structure is conserved for all samples without impurities. A small increase in the lattice parameters were observed for x≥0.05. Morphology and composition were analysed by scanning electron microscopy (SEM- EDX). Impedance spectroscopy measurements form 50Hz to 1MHz were made at different temperatures (25-400°C). The spectra were analysed by Z' vs Z'' plots, which reveal 3 contributions associated to electrodes, grain boundary and grain. From the fits the frequency f) and times relaxation (τ) of the grain were estimated, with values of f∼15KHz and τ∼67µs for 20% Co samples at RT. A dispersion in the permittivity ε* at low frequency (<300Hz) were observed, which increase with the temperature. Each component of ε* converge for frequencies up to ∼300kHz. Finally, a behaviour and activation energy analysis of the electrical conductivity is presented from ln(σ) vs 1/T plots.