Saprobiological investigation using plankton is a part of everyday monitoring practice for determination of water quality in Hungary. However there is an important question: Is this way of using plankton (mainly phytoplankton) good enough and bringing enough information? We can hear, this method is too old and its result are not collateral with different chemical way?s describing saprobity. Another problem of this biological method is being so labor-intensive, demanding a well qualified knowledge on algology and protozoology. To solve these problems and questions we examined saprobiological and the chemical results, describing water quality of tributaries of Hungarian Upper-Tisa, in years 2001-2002. Summarizing results of our investigations, we can say: biological (saprobiological) method of analyses for saprobity is not worse than chemical ways and can give us more information about ecological parameters.