The research on the interactions among multiple ecosystem services is a hot topic in the field of international ecology and geography. The Shiyang River Basin, a typical representative of an arid inland river basin, was used as an example. Several models based on InVEST were used to estimate the value of five key ecosystem services from 2005 to 2015, including water conservation, soil conservation, nutrient retention, carbon storage, and biodiversity. Spatial-temporal differentiation of ecosystem services were also analyzed. In addition, we quantitatively assessed the spatial patterns of interactions among different ecosystem services by applying the partial correlation analysis at a pixel scale. The results were as follows:(1) These ecosystem services presented spatially differential characteristics; the spatial pattern of water conservation, soil conservation, carbon storage, and biodiversity presented the characteristic of having a "low-value zone located at the northeast, whereas there was a high-value zone distributed mostly in the southwest," and the high-value zone for nutrient retention and carbon storage was along the river. (2) From 2005 to 2015, variation characteristics of water conservation, nutrient retention, carbon storage, and biodiversity had an increasing tendency, whereas soil conservation had a decreasing tendency. (3) The five pairwise ecosystem services presented different interactions. The interactions between water conservation and soil conservation, water conservation and nutrient retention, nutrient retention and carbon storage, nutrient retention and biodiversity, soil conservation and carbon storage, and soil conservation and biodiversity presented trade-offs. On the contrary, the interaction between water conservation and carbon storage, water conservation and biodiversity, soil conservation and nutrient retention, and carbon storage and biodiversity were prone to synergistic relationships. Spatially explicit and quantitative assessment of ecosystem service interactions has implications for the planning and management of natural capital and ecosystem services and provides a scientific basis for sustainable development in the Shiyang River Basin. This analysis framework also provides a significant reference with which other river basins can conduct spatial evaluation of ecosystem services.