Abstract: In odder to investigate the effect of shot peening strengthening on fatigue crack growth behavior, taking SUS301L stainless steel for the bottom frame of the subway end as study object, the fatigue crack growth experiment of SUS301L stainless steel was carried out after SP treated for different time using compact tensile（CT） specimen. Fracture morphologies feature, microhardness, optical microstructures and residual stress were analyzed to discuss the effect of SP treatment time on fatigue crack growth mechanism. The results show that the fatigue crack growth rates（FCGR） decrease with the increase of the SP treatment time. Especially at the low ΔK（stress strength factor range）, the FCGR after SP treated for 20min is as low as 25% comparing to 5 min, and 20% comparing to untreated specimen. The enhancement of fatigue crack resistance is due to the martensite transformation, grain refine and compressive residual stress in the surface layer induced by SP treatment.