We studied the soil physical properties and characteristics of plant communities under almost-natural states in enclosed grasslands at the northern foot of the Yinshan Mountain in Inner Mongolia. The objective was to explore the characteristics of grassland communities and soil particles under natural erosion conditions. The results showed that (1) the dominant species in full coverage grassland were Leymus chinensis and Leymus secalinus. The indicator species of grassland degradation, Artemisia frigid, was the dominant species when the vegetation coverage was <40%. The biomass of the grassland community decreased with the vegetation coverage, and the Shannon-Wiener and Simpson indexes firstly increased and then decreased; (2) the fractal dimension was significantly influenced by the grassland coverage at the surface soil; it decreased significantly with decreasing coverage(P < 0.05), and the sand content obviously increased in the surface soil; (3) when the coverage was lower, coarse-grained soil particles were dominant in the 0-1 cm layer, and the accumulative particle difference was up to 1 mm. This showed that the degree of coarse-grained particles increased from the 3-5 cm layer and 1-3 cm layer to the 0-1 cm layer in the vertical soil structure. The cumulative differences of coarse particles were 0.1, 0.25, and 1 mm in the 3-5, 1-3 cm, and 0-1 cm layers, respectively; and (4) with increased coverage, surface soil was covered and effectively protected, and soil particles gradually become finer and the bulk density slowly reduced. Under the almost-natural state, the grassland and soil environment changed hierarchically and diversely, and the patchy changes of grassland vegetation resulted in natural erosion in the enclosed meadow in the Xilamuren grassland.