Grassland is not only the largest terrestrial ecosystem, but also the most diverse ecological resource. Grassland observation monitoring is a systematic observation, monitoring, and recording of grassland production factors and their dynamic changes, aiming at elucidating their connections and development patterns. The Inner Mongolia grassland is currently one of the most diverse and well preserved grasslands in the world, and is an important livestock production base in China. In grassland ecosystems, soil nutrients comprehensively reflect the basic attributes and essential characteristics of soil. Studying the changes in soil nutrients of different grassland types not only reflects the impact of plant communities on grassland soil health, but also provides a basis for soil and vegetation restoration forms, speeds, and directions. At present, research on soil nutrients is mostly found in agricultural planting areas, but there is relatively little research on grassland soil nutrients. Taking Inner Mongolia grassland as an example, relevant research mainly focuses on issues such as microbial diversity and greenhouse gases, with little involvement in soil nutrients, and the supply of relevant data is also very limited. This dataset focuses on the soil nutrient characteristics of available phosphorus, available potassium, total nitrogen, organic matter, total salt, and pH value of eight different "regional grassland types" grasslands in Inner Mongolia Autonomous Region during the turning green, vigorous, and withering stages. The involved areas include five typical grassland types. The grasslands include temperate grassland, desert grassland, natural grassland, five flower grassland, and artificial grassland planting areas. The dataset can provide support for the research and practice of sustainable utilization of grassland resources.