The interaction between exotic invasive plants and soil animal communities is an important aspect of understanding plant invasibility and susceptibility of receptive communities. Consequently, studies on the effects of plant invasion on soil animal communities and their physicochemical properties are becoming increasingly important in determining the effects of plant invasion on ecosystems and the relationship of the invasion mechanism to the underground soil biota. In this paper, we report the soil animal community structure and the soil physicochemical properties of three sampling areas in Jinhua, Zhejiang Province of Eastern China where Solidago canadensis has invaded native plant communities. The objectives of the study are to evaluate how S. canadensis invasion affects the physicochemical characteristics of the plant rhizosphere and the soil animal parameters and to determine whether these parameters can serve as indicators for the invasion density of S. canadensis. Soil samples were collected at three depths over four seasons in different S. canadensis-invaded areas. A total of 9900 individual soil animals, which belong to 14 orders, 11 classes, and 3 phyla, were collected. The most dominant taxa in three invaded areas were Collembola and Acarina. Statistical analysis was performed with the SPSS 18.0 program package. The one-way ANOVA shows that pH, organic carbon, ammonium nitrogen, available K, and available P are significantly different among the sampling areas (p < 0.05), whereas soil water content and soil temperature were not (p > 0.05). The sequence of the diversity indices and the evenness indices were as follows: newly invaded areas< moderately invaded areas < heavily invaded areas. A positive association was found between diversity index and dominance index. The spatial distribution of soil animals in the different S. canadensis invaded areas had obvious surface segregation. Using the non-metric multidimensional scaling method, the soil animals communities were classified into three types. Grey relevant analysis indicated that the soil physicochemical properties had different effects on the key soil animal communities, Ammonium nitrogen produced the most significant effect on soil animals, followed by organic carbon, available P, and finally by soil water content. Therefore, S. canadensis L. invasion changes the soil physicochemical properties (especially the NH₄-N), and then changes the soil animal community used by S. canadensis to expand its invasive range rapidly.