Abstract: This study aims to show the feasibility of the application of Ecological Interface Design (EID) method that may improve operator performance in digitalized system environment such as main control room in next generation nuclear power plant. While cognitive interface design method such as Information Rich Display (IRD) is mainly focused on stereotyped information for the user, EID method helps user’s mental resources to be allocated to tasks that process highly abstract information including diagnosis and situation assessment. However, the sophisticated and relationship-embedded EID displays may cease to be intuitive when many of them are presented without consistently designed common elements. This study showed the suggestion of the consistent elements of EID displays for a digitalized main control room of nuclear power plant taking the example of the control process of Steam Generator (SG) water level. The proposed EID displays were reviewed by domain experts and operators to conjecture how such EID displays might benefit the operator’s decision making. The experience from this study indicates that situation awareness in digitalized interface design may be improved by appropriately designed visualization of abstract information and that operator may be aided by the represented dynamics in EID display.