1. Introduction
Jialing River is a tributary with the largest drainage area of Yangtze River System. National traffic development strategy plans to construct 16 interrelated multistage Navigation-power Junction Projects from the north to the south of Jialing River, 3 projects of which are in Nanchong City——Fengyi Navigation-power Junction, Xiaolong Navigation-power Junction and Qingju Navigation-power Junction. While playing an active part in local economic development, hydroelectric development also has a negative impact on the ecological environment of drainage area, biological diversity and water quality. The water quality of Jialing River is not only related to sustainable development of both sides, but also one of the important factors concerning water environment safety in reservoir area of Three Gorges.Great importance is attached to environmental effect of hydroelectric project at home and abroad, and there are also lots of researches concerning environmental effect of water ecology. As for the water environment condition in Nanchong of Jialing River, at present there are only the physicochemical monitoring conducted by local monitoring station and the diatom research of the drainage area carried out
by Deng Hongping[1] and others, lacking system monitoring of zooplankton and relevant water quality
assessment. As primary producers of water material metabolism and energy flow, zooplankton respond to
water changes and pollutants intrusion quickly. Besides, as for physicochemical indexes of water quality,
standing crop, species composition and diversity of zooplankton can reflect water condition better.as been
widely used globally that evaluating water quality pollution and nutritional level by monitoring
zooplankton[2]. In this paper, the community structure of zooplankton in Nanchong of Jialing River and
water quality condition were investigated and studied, aiming at providing certain theoretical and practical
bases for water environment protection and treatment of Jialing River, resource protection of aquatic
organism and hydroelectric development.