Carbon emissions from land use (LUCE) is an increasingly serious problem in China, and the direction of carbon reduction in urban agglomerations is still unclear. This study aimed to identify the key factors that influence county-level LUCE and their response to LUCE in Beijing-Tianjin- Hebei (BTH) region. Based on multi-source data, our study calculated county-level LUCE and its spatiotemporal variations in BTH from 1992 to 2018. Random forest (RF) and geographically weighted regression (GWR) models were applied to discuss influential factors’ impact and spatial response on LUCE by quantifying relative importance and spatial heterogeneity. The results show that countylevel LUCE in BTH increased by 1300.04×10⁴t, with an average annual growth rate of 46.11% during 1992-2018, and exhibited prominent spatial autocorrelation, with higher-value counties mostly in the core areas and lower-value counties in the suburbs within BTH. The RF estimates were better than the multiple linear regression (MLR) estimates with an improvement in R² from 0.56 to 0.98. Population, urbanization, energy intensity, industry proportion, road network density and technical progress had effective explanatory power for county-level LUCE. In addition, GWR estimation shows that the main influencing factors demonstrated significant spatial heterogeneity, and the impacts of population, urbanization, economic, energy structure and road factors in the central core counties were significantly higher than in the northwestern and southern regions. Industrial structure and technology have the greatest impact in the southern and northeast counties. This study explores different causes of LUCE in different counties of urban agglomerations and the continuation of low-carbon control measures in BTH is required.