The vibration fatigue behavior in socket weld of 304L stainless steel was investigated using experimental and numerical. The vibration fatigue test results indicate that original socket weld at a higher stress tend to occur toe failures while for the case of lower stress failures tend to originate at the root. In addition, the socket welded with groove can improve the fatigue property of weld root, but it has a bad influence on the weld toe. From the simulation results, the groove can decrease the stress concentration factor of weld root, and improve the fatigue property of root; whereas the groove can also increase the tensile residual stress of toe, resulting in having a detrimental effect on fatigue property of toe.