Background and aims: Nitrogen (N) is often the nutrient limiting the decomposability of shoots from macrophytes in wetlands. We aimed to determine the effects of increasing soil N availability on the decomposition of shoots during the standing-dead phase. Methods: We measured the quality of senesced leaves from graminoids and their subsequent aerial decay under different N addition treatments (Control, 0 kg N ha−1 yr.−1; N60, 60 kg N ha−1 yr.−1; N120, 120 kg N ha−1 yr.−1; N240, 240 kg N ha−1 yr.−1) in a temperate marsh. Results: Nitrogen addition increased N concentrations in senesced leaves and often increased phosphorus (P) concentrations. The exponential decay constants (k) of leaves from the N120 and N240 treatments were higher than the control treatment during aerial decay. Nitrogen amounts (in percentage terms) remaining in decaying leaves always significantly decreased after N addition, but the effects on P amounts varied with N addition rates. The nutrient amounts remaining in leaves during the standing-dead phase had negative relationships with the initial nutrient concentrations. Conclusions: Soil N availability exerts remarkable effects on the decay process of standing litters by altering the initial quality, and thus the biogeochemical cycling in temperate wetlands.