Electrical properties of TiO2 are very sensitive to microstructure and phase composition. In the present study, plasma sprayed porous TiO2 coatings containing anatase were prepared using anatase powder and Ar-He-H-2/N-2 plasma gases. The microstructure and phase composition of the coatings were characterized by optical/scanning electron microscopy and X-ray diffraction. The electrical properties of the coatings were investigated by impedance spectroscopy. The prepared coatings were porous, having porosities from 32 to 43% and pores from 1 to 80 mum in diameter. Their phases were mainly rutile, plus 10.0-22.5% anatase by weight. It was evident that the deoxidisation occurred for both the anatase and rutile phases in the coatings. The electrical proper-ties were clearly correlated with the microstructure and phase contents of the coatings. (C) 2003 Elsevier B.V. All rights reserved.