Density and Nematode species composition were investigated in relation to granulometric composition of se“diment at three stations in Rasa Bay (Yugoslavia) during one year. Nematode and copepod densities were higher at station 3 than at stations 1 and 2. Diversity indices showed that stations 1 and 2 had significantly lower species diversity than station 3. But trophic and correspondence analysis showed the great affinity between stations 2 and 3 in contrasts to station 1.