Abstract: This paper investigates the overall design of operation modes in PWRs, and brings forward a design method for operation mode in the advanced PWR. The design method tidies up all aspects of operation modes, arranges the sequence of all aspects, and focuses on the keystones of all design aspects. This paper investigates three operation modes, including Base Load, Load Follow with Boron Change and Load Follow without Boron Change, and brings forward their characteristics and design methods. Finally, the design results of the Load Follow with Boron Change and the Load Follow without Boron Change, which have been accomplished with the guidance of this design method, are presented. The application of these design results in CPR1000 and the 3^rd generation PWR proved that this design method of operation modes in PWR is correct and feasible.