Transport and magnetic properties of Sm 1 - x Sr x MnO 3 (x=0.40, 0.45, and 0.50) thin films fabricated using pulsed laser deposition method (PLD) have been investigated. We found that the insulator-metal (IM) transition similar to those for single crystal samples was achieved by annealing in air and other gases, while as-grown films were insulative in the whole temperature range. From XRD and resistivity measurements, we found that the IM transition takes place due to the release of lattice distortion, not due to modification of oxygen concentration in the samples.