Rapid economic development and interference by human activities in rapidly urbanizing areas cause drastic land use changes, which negatively affect ecosystem function and services. This enormously pressurizes the ecological environment; therefore, it is crucial to assess the spatiotemporal evolution of ecosystem service value (ESV) in such rapidly urbanizing areas. The prediction of land use and ESV and the analysis of the relationship between tradeoffs/synergies can provide a basis for scientific decisions regarding regional sustainable development. Therefore, we analyzed and predicted the effect of land use change on the ESV using the FLUS model (Future Land Use Simulation) and the valuation scale estimation in Foshan City from 2005 to 2025. In addition, we explored the tradeoffs and synergies between ecosystem services using Pearson's correlation and spatial autocorrelation analyses for multiple scenarios in 2025. We demonstrated that (1) the pattern of land use changed significantly and that the degree of land use change in the context of ecological protection was the most moderate. (2) ESV decreased annually, with a total decrease of 1.141 billion yuan from 2005 to 2015; this declining trend was the most obvious under the economic development scenario. (3) The value of four individual ecosystem services, supply, regulation, support, and culture, decreased by 1.95, 5.02, 4.08, and 36 million yuan, respectively. The values of the individual ecosystem services increased in the context of ecological protection. (4) In different scenarios, the ecosystem services showed similar and obvious temporal synergies, especially in the economic development scenario. The southwest and northeast regions were characterized by synergies, whereas the local regions were characterized by tradeoffs. Thus, our study provides a theoretical basis for the regulation of ecosystem function and the construction of an ecological security pattern in rapidly urbanizing areas.