To study the effect of nitrogen addition on the non-structural carbon of species in different ecological niches, we conducted a three-year nitrogen addition experiment on typical abandoned grasslands on the Loess Plateau and analyzed the soluble sugar, starch and non-structural carbon content of species in different ecological niches. The nitrogen gradients were N0 (0 g/(N·m²·a)),N3 (3 g/(N·m²·a)),N6 (6 g/(N·m²·a)) and N9 (9 g/(N·m²·a)). Our study showed that the nitrogen addition mainly affected the storage of non-structural carbohydrates in Bothriochloa ischaemum andStipa bungeanathat occupied the higher niches, while it had little effect on Artemisia sacrorumand weeds. The N6 and N9 treatments significantly increased the storage of non-structural carbon, soluble sugar and starch of Bothriochloa ischaemum andStipa bungeana, especially for the aboveground part. Besides, the relative importance value had significantly positive correlation with the belowground non-structural carbon and starch contents, but had significantly negative correlation with the aboveground soluble sugar content and the ratio of soluble sugar to starch. Our findings are helpful to strengthen our understanding of the carbon storage and distribution characteristics of species in different ecological niches under the background of nitrogen deposition.