Abstract: By modifying and integrating existing concepts and models for describing the structure and function of a river ecosystem,a holistic conceptual model is developed.The hydrological regime,flow conditions and geomorpho-logical patterns are three major habitat factors that have profound impacts on the structure and function of a river ecosystem.The central piece in a holistic conceptual model is to establishing the interrelationship between the life supporting system that is mainly driven by the three factors and the river life system.The human-induced variability of habitat factors and its effect on the river ecosystem are considered during the modeling process.A holistic conceptual model usually consists of four sub-models,which are the 4-dimensional river continuum model,the coupled hydrological regime and ecological process model,the suitability model integrating of hydraulic conditions and biological and life history traits,and the spatial heterogeneity of geomorphology and biocenoses diversity model.The integration of these four models can provide essential aspects of describing the structure and function of a river ecosystem.