In this study, four treatments were installed in Castanopsis carlesii natural forests, a Chinese chestnut plantation and a Sightseeing wood plantation at Sanming City, Fujian Province, China, for a simulated nitrogen deposition experiment:control (CK, 0 g N m^-2 a^-1), low nitrogen (LN, 5 g N m^-2 a^-1), medium nitrogen (MN, 10 g N m^-2 a^-1), and high nitrogen (HN, 15 g N m^-2 a^-1). A solution of NH₄NO₃ was applied as the nitrogen source. The results show that under the experimental conditions, N significantly acidified the soil in the Chinese chestnut plantation, decreasing the mass fraction of P. Over some period, HN treatment can significantly reduce the mass fraction of organic C, total N, and available N; low levels of N deposition can significantly reduce the mass fraction of soil total P and available P; and from six months, only the LN treatment significantly reduced the content of soil K. N settlement generally improved soil pH, organic C, total N, and the available N mass fraction in the Sightseeing wood plantation, and sometimes the impact was significant or extremely significant. In comparison, the LN and HN treatments caused enrichment of the soil total P mass fraction, and the effect of the MN treatment on available P was significant; the LN and HN treatments also significantly increased the mass fraction of K, and the effects of the LN treatment were more stable. With N settlement rose, the acidification of the soil was more significant in the Castanopsis carlesii natural forest; the N settlement of organic C and available P fluctuated significantly. During the experiment, HN treatment significantly reduced the soil total N and available N; LN and MN treatment increased the mass fractions of available N and K. The mass fraction of P showed the same trend of fluctuations in all 4 treatments, and the difference was not significant.