Abstract: The release of nitrogen and phosphorus from sediments has a significant impact on river water quality.To reveal the spatial and temporal distribution characteristics and pollution risks associated with nitrogen, phosphorus, and organic matter in the sediments of the Niulan River, we measured the contents of total nitrogen(TN),total phosphorus(TP),and organic matter(OM) in 23 sediment samples and analyzed their spatial and temporal distribution.The pollution status was assessed using the pollution index method.The results indicated that:(1) The mean values of TN,TP,and OM in the surface sediments of Niulan River mainstream were 0.20,1.58,and 65.45 g/kg, respectively, while those in the tributaries were 0.39,1.77,and 86.39 g/kg, indicating some spatial heterogeneity but not being significantly influenced by water periods.(2) OM was positively correlated with TN and TP in the surface sediments of the Niulan River(P<0.05),showing a certain degree of homology, but TN and TP differed in source and sedimentary behavior.(3) The overall evaluation indicated that the sediments of Niulan River suffered mild organic pollution and severe comprehensive pollution.Furthermore, the total phosphorus(TP) content at 74% of the sampling sites exhibited severe pollution levels, primarily concentrated within the tributaries, this may be attributed to the introduction of exogenous pollution resulting from anthropogenic activities.This study can serve as a scientific foundation for the management of the water environment in Niulan River.