[Aim] Flaveria bidentis (L.) Kuntze, Ambrosia artemisiifolia L. and Bidens pilosa L., three species of exotic plants causing serious damage in China. Understanding the changes in soil nutrients and enzyme activity in the rhizosphere can provide a basis for the study of their invasion mechanism.[Method] We compared and analyzed the changes in soil nutrients and enzymatic activities in different growth stages (seedling, vigorous growth stage, reproductive stage) of F. bidentis, A. artemisiifolia and B. pilosa in Langfang Pilot Plant Base, Institute of Plant Protection, Chinese Academy of Agricultural Sciences.[Result] The growth stages of all three alien plants had significant effects on soil nutrient and soil enzyme activities. The content of available phosphorus and nitrate, and phosphatase activity in the rhizosphere soil of three invasive plants varied with growth stage (increased first and then decreased), they were maximum in vigorous growth stage. The contents of available phosphorus and nitrate in the invasion area were obviously different from that of the native area in different growth stages. The invasion of all three exotic plants reduced the available potassium content in the soil, and increased the activities of urease and phosphatase in the rhizosphere soil.[Conclusion] The registered changes in soil nutrients and enzymatic activity created more favorable conditions for the growth and reproduction of invasives, and facilitated further expansion.