Understanding the intricacies of nitrogen reduction processes and the composition of associated microbial communities is crucial for illuminating the reactions of ecosystems and their functions to persistent nitrogen inputs. To enhance research on the nitrogen reduction process, we determined the potential rates, quantified the relevant genes, and analyzed the macro factors in the sediments of the Yangtze River. The results showed that dissimilatory reduction of nitrate to ammonium (DNRA) dominated the N-reduction processes in the Yangtze River sediment, with average rates of 0.89 ± 0.71 nmol N g