We have investigated the correlation between microstructure, DC resistivity and magnetoresistance of SrRuO3 thin films. The films were epitaxially grown by pulsed laser deposition on (001) SrTiO3 substrates in a temperature range of 690–810°C. According to x-ray measurements, the structure of all films is a mixture of highly oriented domains of strained orthorhombic phases (ortho-I and ortho-II) with different lattice parameters. Films deposited at 780°C show a minimum resistivity (270 μΩcm at 300 K) and a maximum magnetoresistance (8% at 5 K). These films consist mainly of ortho-I phase (a=0.393 nm). Films deposited at 690°C (predominantly ortho-II) have the highest resistivity (up to 1700 μΩcm at 300 K) and lowest magnetoresistance (3% at 5K).