La0.3Sr0.7FeO3 (LSFO) thin films were prepared by RF magnetron sputtering method. The resistance-temperature relation shows that the film favors the semiconductive conduction in the testing temperature range, which arises from the charge ordering of Fe3+ and Fe5+ ions. The charge ordering transition happened at T=250 K. The laser irradiation induces a decrease of the resistance of the film and the maximum relative change in the photoinduced resistance is about 56.3% at T=190 K. The analysis of the resistance-temperature relation using the variable range hoping (VRH) model shows that the intrinsic mechanism of the laser irradiation is the delocalization of the electrons.