中文摘要：

为了研究信江干流浮游植物的时空分布与水质的关系,对信江干流8个监测断面的水质情况及浮游藻类群落结构特征进行调查分析。结果表明,信江流域共观察到7门29科39属85种,其中绿藻门、硅藻门、蓝藻门为优势种群,8个监测点的藻类细胞数量在312～996万个/L之间变动,各监测点之间细胞数量无明显差异。且通过对化学需氧量（COD）、总氮（TN）的测定显示COD浓度在3.87～23.16 mg/L之间,TN平均为4.13 mg/L,总磷（TP）含量较低。Margalef多样性指数与Shannon-Weaver生物多样性指标计算结果与藻类种群数量关系对水质状况感应性差异一致。

英文摘要：

The species structure, dominant groups and distribution of floating algae were investigated at Xinjiang River. The community structure of phytoplankton and water quality on 8 sampling spots of the Xinjiang River were investigated in this study. Chlorophyta, Bacillariophyta, Cyanophyta was dominant. The densities of floating algae from 8 monitoring points were312~996 million / L with no obviously differences in test results between the various monitoring points. The results showed that the data range of chemical oxygen demand（COD） was between 3.87~23.16 mg/L,and total nitrogen（TN） was 4.13 mg/L,with lower TP content. The analysis results with Margalef diversity index and Shannon-Wiener biodiversity index indicated that the water quality in middle and lower reaches of Xinjiang river was in the moderate to severe pollution status, which coincided with the conclusion of the dominant algae instructions.