The zooplankton community during the present study ( autumn 2000 - winter 2001 ) appeared to has low diversity as compared to that found in the whole Egyptian Mediterranean waters. The western side was characterized by higher diversity than the eastern side, which is affected by land based effluents entering the sea from the coastal lakes and the River Nile. The standing crop values indicated poof zooplankton population in the whole study area. The dominance of species showed drastic changes as compared to the previous studies, whereas the previously dominant species are ranked recently as rare species. The identified species exhibited different seasonal patterns of vertical distribution but the majority of them were recorded in the subsurface layer down to 200 m depth.