The heavy metals increase gradually in aquatic ecosystems and its severe impacts in organisms become very observable as a result of the continuous human progress. There is an increasing awareness of the need for methods by which levels of pollution can be monitored so that remedial action can be taken before occurring irreparable damage to the ecosystem. In my book, i studied the effect of different heavy metals on chironomid larvae and observed the severe deformations occurred in the mouthparts of the chironomid larvae resulted from the heavy metals effect and revealed another genus of chironomid "Dicrotendipes sp." which is very sensitive for pollution. My book include general survey on the aquatic fauna found on Sohag governorate and the effect of physico-chemical parameters on diversity of aquatic fauna, some heavy metals concentration in water, sediment and some species samples and relative abundance and annual cycle of Cenocorixa sp. and Chironomus sp. My book is a good reference for researchers interested with environmental studies.