It is required that the fatigue analysis be done for nuclear reactor components consisting of the reactor pressure boundary. Currently, it is certified that the fatigue design curves currently used in the analysis weren’t conservative enough for not considering reactor coolant environment. The article gives some general information related with the regulatory requirements and research work conducted abroad. It introduces coolant environment assisted fatigue experiment based on the domestic austenitic stainless steels and provides the data comparison with the code design fatigue curves. It concludes and recommends the methodology for the nuclear component fatigue design.