Abstract: The author points out:(1)fresh water is deficient in north and acidic in south,(2)acid rain is widely spreaded in this country,(3)water and soil erosion is very serious,(4)fresh water bodies are largely disturbed by crop fields,and(5)both ground and underground water are polluted.It is considered that for each kind of ecosystem,the common task is to preserve fresh water resources.

Key words: Biogeochemistry, Model, Terrestrial ecosystem