Abstract: Ten selected sites were sampled in typical river network region of Suzhou City. The quality of river water and the contents of various nitrogen forms in the sediment profiles were measured. The relationship among various nitrogen forms in the water and sediment was discussed. The results showed that the contents of TN, TP and COD_Cr in the river water exceeded the state standard of water quality, and the water was slightly alkaline. The content of NO^-₃-N (1.10-2.39 mg/L) was higher than that of NH⁺₄-N (0.30-1.70 mg/L) in the water. The water, of which 80% was worse than the Ⅴ grade of water quality, was polluted seriously. The major pollution of the river water resulted from nitrogen. In the sediment, the content of TN ranged from 2.78 to 6.30 g/kg, and it decreased with increasing sediment depth, suggesting that the pollution of rivers was becoming more and more serious year after year. The content of NH⁺₄-N ranged from 37.2 to 228.0 mg/kg in the sediments. It increased with increasing sediment depth, indicating that the content of NH⁺₄-N decreased year after year. The content of NO^-₃-N ranged from 13.1 to 69.4 mg/kg in the sediments. However, the distribution pattern of NO^-₃-N in the sediment profiles in different sampling sites was different from each other. The rapid water flow may be responsible for such a result. Correlation and spatial distribution analysis showed that there was no direct corresponding relationship between the various forms of nitrogen in the overlying water and those in the sediment surface layer in situ, but there was an obvious corresponding relationship spatially. Due to the water flow characteristics, the high content of nitrogen in the sediment was reflected in the overlaying water moving from the east to the west.