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.