[目的] 研究京津冀地区水源涵养功能时空格局变化及其驱动因素，为区域协同发展过程中的生态保护和建设工作提供科学支撑。[方法] 基于研究区基础地理数据和相关参数，利用InVEST模型及水源涵养公式，在ArcGIS平台上采用一元线性回归模型、变异系数和土地利用转移矩阵等空间分析法，分析2000—2019年京津冀地区水源涵养功能时空格局变化特征及主要驱动因素。[结果] ①京津冀地区多年平均产水量为1.87×1010 m3，产水量空间格局为东高西低。②京津冀地区水源涵养量空间格局呈东北—西南燕山、太行山较高，西北—东南坝上高原、河北平原较低。③水源涵养量年际变化较大，多年平均水源涵养量为7.85×109 m3，2002年最低，2012年最高。像元尺度上，2000—2019年水源涵养功能增强区面积大于减弱区，增强区占研究区67.49%，减弱区占研究区32.51%。20 a间水源涵养功能呈“中低波动为主，少数区域波动强烈”的特征，低波动、相对低波动区占93.96%，中等波动、相对高波动和高波动区占6.04%。④京津冀地区水源涵养功能变化主要驱动因素为降水、潜在蒸散发和土地利用变化，典型区水源涵养深度与降水量呈显著正相关，与潜在蒸散发量呈显著负相关。在土地利用变化方面，退耕还林还草等生态工程使林地、草地面积提高，水源涵养能力相对增强；而工矿等建设用地扩展侵占林草、耕地面积，水源涵养能力相对降低。[结论] 京津冀地区水源涵养功能时空格局变化明显，水源涵养功能主要驱动因素是气象因子与土地利用变化。
[Objective] Temporal and spatial pattern changes and driving factors of a water conservation function in the Beijing-Tianjin-Hebei region were analyzed in order to provide scientific support for ecological protection and construction in the process of regional coordinated development. [Methods] Using the InVEST model and a water conservation formula with basic geographic data and relevant parameters for the study area, the temporal and spatial pattern change characteristics and main driving factors of a water conservation function in the Beijing-Tianjin-Hebei region from 2000 to 2019 were analyzed. Spatial analysis methods such as univariate linear regression, coefficient of variation, and land use transfer matrix on the ArcGIS platform were also used. [Results] ① The average annual water yield in the Beijing-Tianjin-Hebei area was 1.87×1010 m3. The spatial pattern of water yield was high in the east and low in the west. ② The spatial pattern of water conservation in the Beijing-Tianjin-Hebei region was higher in the Yanshan and Taihang Mountains (varying from northeast to southwest), and lower in the Bashang Plateau and the Hebei Plain (varying from northwest to southeast). ③ The amount of water conservation varied greatly from year to year, and the annual average amount of water conservation was 7.85×109 m3 (lowest in 2002 and highest in 2012). On the pixel scale, the area of the enhanced area of water conservation function was larger than that of the weakened area from 2000 to 2019. The enhanced area accounting for 67.49% of the study area. The weakened area accounted for 32.51% of the study area. In the past 20 years, the water conservation function could be characterized as being “mainly medium and low fluctuations, with strong fluctuations in a few areas”. The low fluctuation and relatively low fluctuation areas accounted for 93.96% of the total area, and the medium fluctuation, relatively high fluctuation, and high fluctuation areas accounted for 6.04% of the total area. ④ The main driving factors for the change of the water conservation function in the Beijing-Tianjin-Hebei region were precipitation, potential evapotranspiration, and land use changes. The depth of water conservation in typical areas had a significant positive correlation with precipitation, and a significant negative correlation with potential evapotranspiration. With regard to land use changes, ecological projects such as returning farmland to forest and grassland increased the area of forest land and grassland, and relatively increased water conservation capacity. Expansion of industrial and mining construction land encroached on the area of forest, grass, and cultivated land, and water conservation capacity has been relatively reduced. [Conclusion] The temporal and spatial patterns of the water conservation function have noticeable changed in the Beijing-Tianjin-Hebei region. The main driving factors of the water conservation function are meteorological factors and land use changes.