EN
Summary Biological indicators, i.e. plant and animal aquatic organisms, are widely used to determine water quality of rivers in all over theworld. Information aboutwater quality can be derived from the presence/absence of bioindicators, their density, frequency of occurrence, as well as from analyses of biocenotic parameters, such as: dominance structure, total density and biodiversity of various assemblages. Some of these parameters are being taken into account by complex systems ofwater quality evaluation, like: saprobic system, scale of species sensitivity, biotic indexes, and methods based on the present and reconstructed states. Amongst the listed and discribed in the present paper methods the saprobic system based on periphyton and phytoplankton as well as not yet defined biotic indexes using zoobenthos are going to be applied in the new Polish system of river water evaluation, which tries to meet requirements of EU Framewater Directive.