In Wadi El-Rayan area, two successiv lakes at different levels were created as a reservoir for drainage wastewater from agriculture lands. In the area under investigation rotifers were represented by 34 species,of which 6 were recorded for
the first time, namely:Brachionus falcutus, Monostyla quadridentata, Lecane ledwigi, transparency, dissolved oxygen and chlorosity seem to be the most important factors controlling succession of these rotifers in Wadi El-Rayan area. Generally, rotifers were well represented in the two lakes, as compared with the situation in the other areas. Statistical analysis showed a highly similarity index (45.2) between El-Wadi drain and El-Banat canal, followed by first lake and connecting channel (34.3). The second lake revealed the lowest similarity index with other sites and sustained the lowest richness and equitability values of 1.93 and 0.35, respectively.