Recent studies of land use around the world have been shifting from the spatial and temporal dynamics of land use patterns to functional changes in land use and assessments of the sustainability of such changes. The purpose is to identify and measure the products, goods, and services provided by multiple land uses, and the associated environmental and socioeconomic effects. Land-use functions (LUFs) are the goods and services provided by a land use, and summarize a region′s most relevant economic, environmental, and social issues. The LUF framework integrates changes in a large set of indicators to assess the impact of policies on sustainability at various levels of spatial aggregation. It is therefore a good method to trace interrelations between land use changes and functional changes. Here, we identify 10 relevant LUFs for China in accordance with three dimensions-economic, environmental and social dimensions of sustainable development, investigate methods for their assessment, and analyze spatial and temporal changes in the functions for 31 provinces and municipalities from 1985 to 2005. The LUFs include social functions (the provision of work, human health, and living conditions); economic functions (cover land based production, artificial land-based production, and transportation); and environmental functions (the provision and maintenance of resources, pollutant reception, maintenance of ecological processes, and conservation of rural landscapes). Significant spatial and temporal variations were observed. Of the 10 LUFs we identified, the provision of work increased and decreased in different periods, whereas maintenance of ecosystem processes remained stable, but in a critical condition. Other LUFs improved, including human health, transportation, living conditions, land-based production, artificial land-based production, provision and maintenance of resources, pollutant reception, and landscape and cultural services. In general, the overall LUF of China has improved from 1985 to 2005, and coefficient of variation of LUFs among the Chinese provinces has decreased from 0.63 to 0.27, suggesting that the regional disparity of LUFs has decreased, except for the functions related to the provision of work and the conservation of rural landscapes. Maintenance of ecological processes remained stable over time, but the rest of the LUFs tended to exhibit improvement patterns from 1985 to 2005. Of the 10 LUFs that we studied, the pollutant reception function was weakest, suggesting that there is high potential to improve this LUF by enhancing environmental conservation measures, and that this improvement is necessary. Rural landscape conservation improved due mainly to the implementation of programs to convert agriculture on sloping land to less damaging uses throughout the country, leading to the conversion of vast areas of arable land into forest and grassland. The main factors leading to such differences are variations in natural resources and socioeconomic development; land use policy plays an especially important role. For instance, land-based production and artificial land-based production have increased slowly in the northwestern part of the country, where economic development level is relatively low, whereas the human health function is improving in regions with a relatively low population density and a high per capita grain and livestock production. There is great potential to improve LUFs both nationally and in specific regions. Supporting scientific management of land resources will require a systematic land use policy targeted at LUFs and specific to each region, and the consequences of LUF changes must also be considered.