Environmentally assisted fatigue(EAF)is an important aging mechanism for reactors with water as coolant,which has significant influences on the fatigue life of critical sensitive components in primary circuit of nuclear power plants.In this paper,the EAF screening process of critical sensitive components and the calculation formula of environmental fatigue correction factor(Fen)deriving from the United States are introduced.Meanwhile,the results of EAF key sensitive part screening for the license renewal units in the United States are statistically analyzed.Referring to the EAF analysis method of the United States,the critical sensitive components of the primary circuit of Units 1 and 2 in a domestic plant are selected.The processes,methods,and cases have important guiding and demonstration significance for EAF analysis in the domestic nuclear power plants.