Abstract: The coordinated instrumentation control and protection technology between reactor and steam turbine generator (TG) usually is very significant and complicated for a new construction of nuclear power plant, because it carries the safety, economy and availability of nuclear power plant. Based on successful practice of a nuclear power plant, the experience on interface design and hardware architecture of coordinated intrumentation control and protection technology between reactor and steam turbine generator was abstracted and researched. In this paper, the key points and engineering experience were introduced to give the helpful instructions for the new project.