[en] As a new type of research reactor, no experience can be used for the design and implementation of the power regulating system. So it is necessary to determine the algorithm, parameters and its dynamic characteristics through Modeling and Simulating for reactor power regulating system. This paper described the results of the study on a Simulated close-loop control system comprising the reactor mockup, the control equipment, the step motor and its driver. The influence of rod operating area, of fuel burnout on dynamic characteristics of the control system were discussed. The dynamic characteristics under positive disturb and negative disturb were compared. The study and its results would provide theoretical and methodological basis for the design and implementation of the power regulating system, of the new type nuclear reactor. (authors)