Abstract:Nutrients and particle size composition in surface sediments in the Guangzhou section of the Pearl River were measured. Granularity effect and distribution characteristics of nutrients were studied.Results showed that all of the nutrients appeared the distribution characteristics of "low-high-low" on longitudinal distribution in trunk stream on whole. There were significant positive correlations among organic matter, to-tal nitrogen,and total phosphorus.Total nitrogen was highly linearly correlated with organic matter,with regression coefficient reaching 0.950. Nutrients were significantly negatively correlated with sand fraction and positively correlated with powder sand fraction. However, nutrients were not significantly correlated with clay fraction.The correlations between nutrients and particle size composition would enrich the content of granularity effect of pollutants in sediment.