The effects of nitrogen and phosphorus on algal community structure in modellingmulti-cell stabilization pond systems have been observed in green house during spring tosummer in 1988 and 1989. The results showed that when the concentration of TP were allkept around 7 mg/l,and the TN were changed from 13.5,24.8,44.4 to 77.4mg/l in the rawsewage of four experimental series,the cell number,species composition,diversity index andprimary production of algae in sewage were increased with the TN concentration incre...