Abstract: Based on a summary of past experiences and lessons,it is suggested that for the formulation of river basin development strategies,the river basin must be viewed as an ecosystem,and the economic,social as well as environmental benefits must be considered as the criteria for comparing and deciding alternative designs.Referring to the methods and proceduresfor river basin development and management,more detailed recommendations are given in thepaper.It is also suggested that the overall planning of water and land resources in the riverbasin is the key for its development and ecological construction.

Key words: Soil protozoa, Bio-indicator, Environmental pollution, Eco-toxicity diagnosis