Shot peening was applied to 1Cr13alloy for different periods of time(5min,10min,20min and 40min) and the effects of this treatment on the selective oxidation behaviour at 800℃ for 100h have been studied. The experimental results and metallographic analysis show that shot peening forms a micro-crystalline coating on the surface of 1Cr13alloy, which lowers the critical Cr content to form continuous selective oxide scales, and thus the mass gain of the oxide scales is significantly decreased and the spallation of the oxide scales is also reduced. Shot peening promotes the formation of a protective and selective scales, thus improving the high-temperature oxidation resistance of the stainless steel greatly. The effect of shot peening for 10～20min is the best.