T he chemical composition of zooplankton has been studied during I QV^^OOO along the coastal waters of Alexandria from 8 stations representing different areas subjected to different types and quantities of landbased activities. The annual averages of carbon-nitrogen and phosphorus contents during the period of study were 45-3%, 5.84% and 0.42%, respectively. The N:P ratio for zooplankton was 13.9 while that of C:N ratio was. 7.75> i.exemarkably higher than that reported for marine organisms. Organisms collected opposite to sewage discharge were characterized by high chemical components while opposite to industrial discharge, the zooplankton chemical components were minimum. The chemical composition of zooplankton is mostly affected by the variations of available food represented by chlorophyll a concentrations.