In order to compare the effects of laser shock peening (LSP) and ultrasonic shot peening (USP) on fatigue property in 1Cr11Ni2W2MoV stainless steel, vibration fatigue tests of three different samples are conducted at 20 ℃, X-ray diffractometry (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are used to investigate the mechanism of fatigue property improvement. Experimentally, the fatigue lives of 1Cr11Ni2W2MoV stainless steel after USP and LSP are increased by 88.2% and 280.1%, respectively. The surface residual stress after LSP is -810 MPa and the one after USP is -545 MPa, and the compressive residual stress depth after LSP and USP is 1.8 mm, 0.4 mm, respectively. The surface microhardness after LSP and USP increases from 392 HV to 434 HV and 405 HV, respectively. The microstructure studies demonstrate that USP has an advantage in microstructure refinement and surface nanocystallines. We come to the conclusion that the residual stress and the small influence to the roughness make great contributions to the superiority of LSP in the improvement in fatigue property of 1Cr11Ni2W2MoV stainless steel over USP at 20 ℃.