We investigate the effect of annealing temperature on the preferentially (110)-oriented CaRuO3-delta, (CRO) thin films directly prepared on Si(100) substrate by rf magnetron sputtering. Crystalline quality and electrical transport properties of the CRO thin films were modified by post-annealing treatment. It was obvious that 700 degrees C post-annealing brought about excellent metallic characteristics with the elevation of carrier concentration and mobility. From this result, we suggested that enhanced (110) orientation, and the ratio of chemical composition Ru4+/Ca2+ ion were responsible for the transport properties of CRO thin film. (C) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.