Novel one-step mechanical processing was proposed to prepare LSM/ScSZ composite particles from the starting raw powders of LSM (strontium doped lanthanum manganite) and ScSZ (scandium stabilized zirconia) fine powder. In this paper, the properties of composite particles made by this method and the properties of the resultant cells were evaluated. As a result, LSM/ScSZ composite particles were obtained by only 10 min mechanical processing using three kinds of raw powder materials of LSM and ScSZ fine particles without extra heat. The maximum power density of the cell made by the composite particles at 800 degrees C reached 320 mW/cm(2). It was higher than that made by commercially available LSM nanosized powder. Besides, the polarization resistance of the cathode made by the composite particles at 800 degrees C was 0.5 Omega cm(2) which was lower than that made by using commercially available LSM powder. It suggests that the proposed method is very promising for producing high quality composite particles used for SOFC cathodes by more simple and energy-saving way. (C) 2013 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.