Environmental parameters as well as heavy metals (cadmium, lead. copper and zinc) in water and sediment have been studied in the eastern section of Delta coast-Mediterranean Sea, This research has been done during four seasons from summer 2002 to spring 2003. Both zooplankton and benthic invertebrates abundance in sediment have been estimated in Damietta coast. Most of environmental parameters showed higher concentrations during summer and autumn 2002 than that values recorded in winter and spring 2003. Dissolved oxygen concentration was decreased to reach (0 mg/1) at New Damietta drain, while BOD concentration increased at the "same site. due to the increased quantity of industrial drainage water which adversally affected the biodiversity. Lead values in water showed high concentration (0.08 mg/1) at sites 4 & 2 during 2002 & 2003 respectively. This increase may be due to the activity of maritime ports for both commercial transport and fishing at Ezbet el-Borg. Heavy metals were magnified 100-1000 times in sediment more than that recorded in water. The concentrations of heavy metals in water and sediment were in the order of Zn> Cu> Pb>Cd. Sites 4 & 3 showed higher abundance of invertebrate species than other sites. Biodiversity of invertebrates in sediment was higher at sites 1 and 3. and that may be attributed to the high concentration of DO in water and TOC in sediment. Twenty two species of zooplankton of 6 phyla were identified. The biodiversity of zooplankton during spring 2003 was hieher than that recorded durinu summer 2002.