Structural characteristics of macrophyte communities for evaluation of the ecological state of the small rivers in the Leningrad region are used, The comparison of evaluation results of water quality with the help of hydrochemical parameters and characteristics of vegetative cover is done. For rivers with high environmental quality the narrow ranges of structural characteristic values of macrophyte communities are found. We consider this state to be a normal one. An example of interrelations of estimation components for the ecological situation in water bodies is given.