Lake Poyang catchment,a large scale system with high spatial variability in land surface characteristics,was chosed to be the study area in this paper.Catchment hydrological and lake hydrodynamic processes are the main processes in the system.To represent the interaction of hydrological and hydrodynamic processes between the lake-catchment and reflect the mechanisms for different processes,an integrated model was set up.The integrated model used three sub-models with different functions to perform spatial linkage and it included a catchment distributed hydrological model WATLAC,a lakeside plain area runoff model and a lake hydrodynamic model MIKE 21.The integrated model used an input-output linkage approach and involved sequential execution of individual sub-model,i.e.,the discharges of major rivers and runoff of plain area were used as input conditions to drive the lake hydrodynamic model,and thus simulate the lake water level in response to catchment discharges.We used the river discharges of six hydrological stations and average base flow index as well as water levels of four lake stations as state variables to calibrate the integrated model.The Nash-Sutcliffe efficiency (E_ns) and determination coefficients (R²) of daily river discharges vary from 0.71-0.84 and 0.70-0.88,respectively and vary from 0.88-0.98 and 0.96-0.98 for lake water levels.Results indicate that the integrated model can ideally reproduce the response of lake water level to the catchment rainfall-runoff process.The simulated lake lev-els further demonstrate that the integrated model has the ability to obtain the detailed hydrodynamic characteristics in space and time.The proposed model can be used as an effective tool to quantitatively reveal the hydrological and hydrodynamic processes of lake-catchment system in response to climate change and human activities in the catchment.