ake Honghu is a typical shallow lake and rich in aquatic plants in the middle reach ofthe Yangze River. It is an example of an important of type wetland in China. This paper re-ports on the chemical structure of the ecological environment in the lake. In the lake water,Ca￣(2+) and are major cation and anion ,alkal capacity is rather low,acid capacity is 1. 2×10￣(-3)-2. 0×10￣(-3)mol/l H￣+. The equilibrum course of carbonates is the basic factor to controlthe geochemical process of water quality.Aquat...