Afforestation is known to be the main source of restoration of degraded soil fertility and a driving force of soil processes. Plant species affect quantity and quality of carbon resources in the rhizosphere, which influence the composition and diversity of microbial community in these environments. Different plant species promote proliferation of different microbial communities by releasing different amounts and types of root exudates. Moreover, plants may directly or indirectly affect soil nutrient availability by altering soil enzyme activities through releasing extracellular enzymes and/or altering microbial community that is known to be major contributors of enzyme activities in soil. However, few studies have been conducted to elucidate the effects of afforestation with different tree species on enzyme activities and nutrients in soil. To evaluate the changes in enzyme activities and nutrients in soil after 26 years(1987-2013) of afforestation with different tree species, four plantations stands with dominant tree species(e.g., Cercidiphyllum japonicum[CJ], Pinus tabulaeformis[PT], Larix kaempferi[LK], and Pinus armandii[PA]) were selected, and a native broad-leaf forest(QC) was used as control. Four plantations were cultivated under similar site conditions and same planting patterns. Seven soil enzymes including soil urease, acid phosphatase, invertase, β-glucosidase, dehydrogenase, catalase, and polyphenol oxidase, their activities, and soil nutrients were determined. Our results showed that:(1) Afforestation significantly influenced soil enzyme activities. For example, compared with QC, afforestation with CJ, PT, LK, and PA decreased soil acid phosphatase, β-glucosidase, dehydrogenases, and catalase activities, whereas activity of soil urease was significantly higher in CJ and LK plantations than in other stands;(2) Afforestation also significantly affected soil nutrient content. Except for total phosphates, soil total organic carbon, total nitrogen, water extractable carbon and nitrogen, NH₄⁺-N, and NO₃^--N were significantly lower in the four plantations than in the QC stand;(3) Enzyme activity and nutrient availability was higher in LK and CJ plantations, than in PT and PA plantations;(4) Soil enzyme activities were correlated to soil nutrients depending on specific enzymes. Except for invertase and catalase, activities of other five soil enzymes examined in this study were sensitive to changes in soil environment, especially to the nutrient content. Our results suggested that high-density afforestation with monoculture decreased soil nutrients and soil enzyme activities. Additionally, deciduous or broad-leaved tree species(e.g., LK or CJ) can be appropriate for restoration of soil fertility by afforestation and structure modification of monoculture plantation. We concluded that soil enzymes are a good indicator of change in soil fertility induced by afforestation with different tree species or land use change.