Based on the conservation laws of mass, energy and momentum, a lumped-parameter dynamical model is proposed for the nuclear heating reactor cogeneration plant NHR200-II that can be served for electricity production and district heating. This model is mainly composed of the dynamics of the reactor, steam generator, turbine, deaerator, heat exchangers and secondary steam flow network. Then, the steady and transient validation of this lumped-parameter model are given based on the comparison between the parameter values given by this model and the model for plant design, which shows that both the steady and transient errors are acceptable, and which further reveals that the thermal resistances and capacities of this model are properly given. Finally, the open-loop responses under different exterior disturbances such as reactivity and coolant flowrates as well as the closed-loop responses under the cases of power ramp and switch are all given by the numerical simulation software developed based upon this newly-built lumped-parameter model for NHR200-II plant, where the rationality of the responses are analyzed from the viewpoint of plant physics and thermal-hydraulics. This model can be utilized for not only the control system design but also the development of a real-time simulator for the hardware-in-loop verification of control systems. (C) 2017 Elsevier Ltd. All rights reserved.