This paper analyses the present situation of the study and appliance of rainfall runoff yield model.Anew rainfall runoff yield model supported by GIS and remote sensing applied in river network areas of plain is putforward.The model considers the elements of underlying surface and storm as the factors yaring with changes ofspace and time,and uses remote sensing technique to timely acquire the variable underlying surface factors,such asantecedent soil moisture content.In addition to that,proceeding from the physical causes of the yield,the paper notonly sets up the mathematic model which reflects the inner mechanisms of the runoff yield and is easy to be used,but also simulates the yield and confluence state of the runoff in every small temporal-spatial units of the area.Allof these make the model have a high adaptability.Its application has shown a good agree with the actual condition.