A country's natural resources and economic resources form the basis of its regional sustainable development. Based on an improved model of the relative carrying capacity of resources, we calculate the relative carrying capacity of the population and that of the economy in the Tarim River Basin in Xinjiang from 2000 to 2011. We also discuss the temporal evolution and the difference in characteristics of 42 prefectures and cities in the Tarim River Basin. Most of the data were collected from the Xinjiang Statistical Yearbook (2000 to 2012), the Xinjiang City County Building Statistical Yearbook (2000 to 2011), and the Xinjiang Water Resources Bulletin (2000 to 2011). The Tarim River Basin is China's largest inland river basin, and is located in an arid area with a fragile ecological environment, poor local water resources, and a limited oasis area. In recent years, population growth, industrial development, and urbanization have accelerated the disparity between the supply and demand of land and water resources in the Tarim River Basin. The implications from this study are as follows: (1) The improved model of the relative carrying capacity of resources has a certain practical value in optimizing the relative carrying capacity of resources evaluation model. (2) In comparison with Xinjiang, the Tarim River Basin can be characterized as an overpopulated area with a surplus economy from 2000 to 2011. (3) Compared with Xinjiang, land resources are relatively plentiful in the Tarim River Basin, but water resources are relatively scarce, which restricts the population and economic development. Economic development relies on traditional agricultural production in the Tarim River Basin. Thus, in the Tarim River Basin, while land is a relatively advantageous resource, water can be considered as a relatively disadvantageous resource. In future, a more concerted effort needs to be made to improve the efficient use of water resources in the area, as well as to exploit the comparative advantage offered by the relatively abundant land resources. (4) The 42 prefectures and cities in the Tarim River Basin display significant spatial differences in terms of the relative carrying capacity of the population and the economy. Significant differences are also found between the sub-river basins in terms of these factors, which is a reflection of the complex physical geography of the area. (5) Based on the relative carrying capacity of the population and the economy, we classify the 42 prefectures and cities in the Tarim River Basin into four groups, and then summarize the evolution of each group's temporal characteristics and development strategies. After nearly 12 years of development and evolution, the relative carrying capacity of the population and the economy in the Tarim River Basin are still highly unbalanced in terms of the area's spatial pattern and distribution. The counties and cities in group B, which have a relatively insufficient economic scale, should become the key development areas in the Tarim River Basin. In contrast, the counties and cities in group C, which are relatively saturated in terms of their economic scale, but have a relatively small population, should become optimized development areas.