The Eastern Harbor is receiving several kinds of untreated pollutionو which affect zooplankton distribution along the harbor. For this reason, the present work aims to study of the spatial and temporal distribution of the zooplankton community in the harbor and shed some light on their diversity and abundance. Four seasonal cruises (spring 2017, summer 2017, autumn 2017, and winter 2018) were carried out at nine stations along the Eastern Harbor to achieve the aim of this work. The result revealed that the zooplankton community in the Eastern Harbor comprised 87 species and other immature forms belonging to 19 groups with a total standing crop of 4984.31 ind./m³. Copepoda was comprised of the main bulk of zooplankton, it represented by 39 species and constituted 81.97% of the total zooplankton count. Polychaeta (4.97%) was the second abundant group, followed by Mollusca (3.85) and Cirripedia (2.91). Foraminifera, Tintinnida and Rotifera were the most diverse groups after copepods, they represented by 12, 10, and 5 species, respectively. Nematoda, Cirripedia, Decapoda, and Echinodermata were represented in the present study only by immature stages. Seasonally, zooplankton was flourished during winter and declined during autumn. Spatially, the abundance was high at the water inlet to the harbor (Boghaz 1 station) and low at the water outlet from the harbor (Boghaz 1 station) and at El-Qalaa station outside the harbor. The ecological diversity indices were widely ranged among investigated stations within four seasons. The fluctuation of diversity indices values between stations confirms and indicates that there are disturbances in zooplankton distribution between stations during the study period.