ABSTRACT: The main aim of the study is to describe one physically based rainfall-runoff model with distributed parameters. The model runs at any space and time resolution. The filling in missing data is possible but unnecessary. Many classifications of soil parameters, parameterization of land use types and many determination methods of e.g. evapotranspiration allow reach the more exact results. The determination of net radiation balance and the whole energy balance include the influences of cloudiness, slope orientation and hill shading. Transformation of rainfall excess to runoff is solved by approximation of diffuse wave. Calibration and efficiency are composed in the model. The FRIER model can serve as a complex tool for solution of hydrological and other problems, e.g. water balance calculation, discharge simulation, flood prediction, impact of change in land use and climate and others.