Abstract: This paper presents a hydrological cycle system model based on reservoir model concept to model hydrological cycle processes in Zhalong wetland.It is divided into 9 reservoirs based on the topography and the project construction Each reservoir is modelled based on water balance function.The model works using the input data from 1971 to 2003.The parameters of the model are calibrated by the 11 years (1971-1981) outflow runoff data.The validity of the model is verified by the 6 years (1982-1987) outflow runoff data and 12 flooded areas obtained from Landsat TM images.The efficiency coefficient of outflow runoff is nearly 0.90 and the relative error less than 3.0%.The modeled flooded areas are also satisfying.The results show that the proposed model has a good performance in modelling wetland hydrological cycle system.