Abstract: Based on the investigation of soil properties and plant community characteristics in the subsidence and non-subsidence areas of coal mine in the Hulunbuir Prairie, the changes in soil water content, soil nutrients, community composition and diversity were analyzed. The relationship between soil properties and community diversity was studied, and the soil-plant system was evaluated using a factor analysis method. The results showed that: (1) Soil water content decreased by 4.8% in the subsidence area(P < 0.05). The soil water content significantly decreased by 8.4% in the middle of the subsidence slope compared with the same slope in the control area (P < 0.05). The average content of soil total potassium, total nitrogen, total phosphorus, organic matter and available potassium in 0-60 cm soil decreased by 17.8%, 28.9%, 38.0% and 46.5%, respectively, due to the subsidence (P < 0.05). There was significant loss of soil nutrients in the middle and lower slopes, the content of soil total nitrogen decreased by 29.7% in the middle slope, and the content of soil organic matter and soil available potassium decreased by 54.1% and 64.1%, respectively (P < 0.05). (2) The plant species declined by 28.6%-37.0% compared with that in the control area. The importance value of the original dominant species Leymus chinensis and Stipa baicalensis decreased, while the species and number of xerophytes such as Allium bidentatum and Carex duriuscula increased and the plant community degraded in the subsidence area. The community Margalef index, Shannon-Wiener index and Simpson index were significantly lower than those in the control area (P < 0.05). (3) There was a significant correlation between soil properties and species diversity indices. The correlation coefficients between total phosphorus, total nitrogen, organic matter, and available potassium and species diversity indices were higher than 0.5 (P < 0.05). Soil total nitrogen was a key factor affecting community diversity. (4) The soil-plant system of each sample plot in the subsidence area was degraded compared with that of the control area, and the degradation at different positions was middle-part > upper-part > lower-part along the subsidence slope. This study showed that under the influence of subsidence, soil moisture and nutrients were lost, community diversity decreased, soil-plant system was obviously degraded, and the middle part of the slope (the subsidence marginal area) was severely degenerated.