Zooplanktons are cosmopolitan organisms and impacted by environmental factors. So, freshwater zooplanktons were surveyed in three different sites at Menoufia governorate, Egypt from March 2017 till February 2018. Zooplanktons were collected monthly in order to evaluate the changes of its diversity and population density in the light of some environmental conditions. Three sites were selected at Bahr Shebeen Nitoltic canal, two of them were at Shebeen El-Koom city and the third was at Menouf city. Physico-chemical parameters values varied according to the season or the site. Nineteen species belong to 6 phyla, Protozoa, Cnidaria, Platyhelminthes, Nematoda, Rotifera, and Arthropoda were recorded. The total number of collected zooplanktons showed differences in population density between sites. The highest percentage of individuals (89.52%) was recorded at the least polluted site with heavy metals concentrations, followed by (8.75 and 1.73 %) of the other sites. Classes Turbellaria, Monogonota and Crustacea were considered as abundant. However, Ciliophora, Hydrozoa, Secernentea, Bdelloidea and Insecta were common species. Insect larvae and copepods recorded the highest densities at the least polluted site (P = 0.04, ANOVA). Shannon diversity index, richness and evenness indices recorded the highest values at the least polluted site, followed by the other sites. It can be concluded that zooplanktons community structure and density efficiently responded to inter-specific variations of habitats with special reference to pollution type and less to environmental factors.