###### Abstract  
Land use is closely related to the sustainability of ecological development. This paper employed a patch-generating land use simulation (PLUS) model for the multi-scenario simulation of urban agglomerations. In addition, mathematical analysis methods such as Theil-Sen Median trend analysis, R/S analysis, Getis-Ord Gi* index and unary linear regression were used to study the temporal and spatial evolution characteristics of net primary productivity (NPP) for the impact of land use changes on NPP in urban agglomerations from 2000 to 2020 and to forecast the future trend of NPP. The results indicate that urban expansion is obvious in the baseline scenario and in the ecological protection scenario. In the scenario of cropland protection, the urban expansion is consistent with the land use plan of the government for 2035. The NPP in Beijing decreased gradually from northwest to southeast. The hot spot areas are concentrated in the densely forested areas in the mountainous areas of northwest. The cold spot areas are mainly concentrated in the periphery of urban areas and water areas. The NPP will continue to increase in forest and other areas under protection and remain stable in impervious surfaces. The NPP of Beijing showed a strong improvement trend and this trend will continue with the right ecological management and urban planning of the government. The study of land use in urban agglomeration and the development trend of vegetation NPP in the future can help policymakers rationally manage future land use dynamics and maintain the sustainable development of urban regional ecosystems. * [2022] 14755 serious land degradation and ecological environment problems [11]. However, [PERSON] [7] found that the NPP of new urban land in 2019 was better than that of original urban land before 2010. The human activities, mainly ecological restoration projects, made the vegetation coverage on the Loess Plateau show a significant upward trend in the past three decades [12]. As a metropolitan center, Beijing City is the capital of China with great land use transformations which is worthwhile researching. Discussing the land use transformation on the influence of vegetation NPP and whether the future changes are consistent are essential for alleviating the conflicts between sustainable development and environmental protection. Previous studies of NPP have mainly focused on the two parts. The first part is the establishment, application and optimization of the NPP calculation model [13; 14]. The other part is exploring the response mechanism of NPP by taking climate factors and human activities as the main driving factors [15; 16]. Meanwhile, the change trend and the future development of NPP are also worth studying. The combination of Theil-Sen Median trend analysis and Mann-Kendall test is used to detect the trend of spatial variation in NPP widely [7; 17]. This combination can eliminate the noise of original data and are very robust [17]. [PERSON] [18] predicted a decrease in net ecosystem exchange and NPP by approaching the most extreme climate conditions. [PERSON] [19] assessed the characteristics of NPP due to future climate change and CO2. These simulation results are realized by predicting the driving factors of NPP instead of the NPP itself. Other scholars simulate NPP in the future through the change trend of NPP in the past [20; 21; 22]. In addition to analyzing the changing trend of NPP and its driving factors, it is necessary to study the future trend of them during rapid urbanization. To predict the future land use (one of the driving factors of NPP), many kinds of land use simulation models have been developed, such as cellular automata (CA) [23; 24; 25; 26], conversion of land use and its effects modeling framework (CLUE) model and its improved model [27; 28; 29], future land use simulation (FLUS) model [30] and patch-generating land use simulation (PLUS) model [31; 32]. However, the CA model is weak at revealing the underlying drivers of land use change [33].