To investigate the response of soil exchangeable salt-based ions and soil carbon and nitrogen content to nitrogen addition under two land use modes in the Three Gorges reservoir area, the changes of soil exchangeable Ca²⁺, Mg²⁺, Na⁺, K⁺ and NO₃^--N, DOC in forest and orchard soils in Zigui County, Hubei Province were investigated by indoor soil column leaching simulation experiments at four different nitrogen additions. The results showed that with the increasing of nitrogen addition amount, the leaching loss amount of exchangeable base cations in the forest soil increased significantly (p < 0.05), while that in the orchard soil did not change significantly. The total leaching loss amount of exchangeable base cations and the leaching loss amount of each base ion in the forest soil were higher than those in the orchard soil. Compared with the blank control (N0), in the forest soil under the three nitrogen additions (N1, N2 and N3), the total leaching loss amount of exchangeable base cations increased by 1.78%, 4.45% and 8.49%, respectively, and the leaching loss amount of NO₃^--N increased by 89.321%, 77.73% and 157.25%, respectively, indicating that nitrogen addition increased the leaching loss of NO₃^--N from the soil and thus took away exchange cations from the soil. The cumulative loss of DOC from forest soils decreased by 1.15% and 9.53% under N2 and N3 treatment, respectively, while it in orchard soils decreased by 15.55%, 5.88% and 17.16% under N1, N2 and N3 treatment, respectively. Compared with orchard soils disturbed by human, the leaching amount of exchangeable based cations in forest under a relatively natural state was more sensitive to nitrogen addition. The research showed that the increasing of nitrogen addition increased the leaching loss amount of exchangeable base cations and NO₃^--N in forest soil and decreased the leaching loss amount of DOC in forest and orchard soils.