Abstract: The condenser is a critical component that affects the efficiency and performance of nuclear power plant. In order to make the condenser work under high efficiency and safety, advanced simulation methods for condensers need to be developed. The steam surface condenser commonly used in nuclear power plant was taken as the research object. Dissolved gas such as air was taken into consideration. The idea applied in distributed thermodynamic modeling was used to establish the mathematical dynamic model of the condenser, and then the dynamic responses of condenser to the step change of different control parameters were obtained. The predictions from the models were compared with the experimental data, and the agreement is satisfactory. It is found that the simulation model established in this paper is correct and reasonable.