[目的] 揭示陕西省延安市退耕还林还草进程中土壤侵蚀强度时空递变规律，为水土保持规划与评价、土地资源管理和生态修复等问题的研究提供参考。[方法] 基于延安市1990—2020年遥感影像解译结果及水利部土壤侵蚀分级标准(SL190-2007)，引入偏移份额模型对延安市土壤侵蚀情势进行分析。[结果] ①延安市土壤侵蚀变化情势整体表现为北部剧烈，南部缓和，并以2000年为拐点实现从侵蚀加剧到逐渐恢复的转折，其平均土壤侵蚀模数从最高时4071.38 t/(km2·a)下降到2 366.19 t/(km2·a)。②主要由轻度、中度和强烈3种土壤侵蚀水平的变化影响整体土壤侵蚀情况变化。③偏移份额模型可以用于研究退耕还林还草工程对土壤侵蚀情况的偏移效应，但其应用过程仍存在精度较低、生态学意义不明确等问题，有待进一步改进和研究。[结论] 延安市北部、中部地区林地增长迅速，南部地区草地增长迅速，林地、耕地及不同覆盖度草地之间的比例结构变化是土壤侵蚀情势发生阶段性变化的主要原因。
[Objective] The temporal and spatial changes in soil erosion intensity when farmland is returned to forest or grassland in Yan’an City Shaanxi Province were analyzed in order to provide a reference for researches on the planning and evaluation of soil and water conservation, land resource management, and ecological restoration. [Methods] Based on the interpretation results of remote sensing images of Yan’an City from 1990 to 2020 and standards for classification and gradation of soil erosion set by the Ministry of Water Resources, PRC (SL190-2007), soil erosion in Yan’an City was analyzed using the shift-share model. [Results] ① The graded change of soil erosion in Yan’an City as a whole was severe in the north and mild in the south, and the year 2000 was the inflection point where the situation changed from aggravated erosion to gradual recovery. The average soil erosion modulus in Yan’an City decreased from a maximum value of 4 071.38 t/(km2·yr) to 2 366.19 t/(km2·yr). ② The overall change of soil erosion was mainly affected by three erosion levels (slight erosion, moderate erosion, and severe erosion). ③ The shift-share model might be useful in exploring the offset effects of the grain for green project on soil erosion in the districts and counties of Yan’an City. Nevertheless, its application needs to be further investigated and improved due to issues such as accuracy and precision, as well as its ecological significance. [Conclusion] The forest land in the north and central part of Yan’an City increased rapidly, while the grassland in the south increased rapidly. The proportional changes among forest land, cultivated land, and grassland with different coverages were the main reason for the periodic changes in soil erosion.