Forest soil microbial activity is an important aspect of soil properties, and the number of the three kinds of microorganisms (bacteria, fungi, and actinomycetes) is an important indicator of the level of soil microbial activity. To understand the effects of increasing nitrogen deposition on soil microorganisms, an in situ experiment was conducted in a natural evergreen broadleaf forest in Ya'an City, Sichuan Province. We conducted the field experiment between November 2013 and December 2014. Four levels of nitrogen deposition were set:control (CK 0 kg N hm^-2 a^-1), low nitrogen (L 50 kg N hm^-2 a^-1), medium nitrogen (M 150 kg N hm^-2 a^-1), and high nitrogen (H 300 kg N hm^-2 a^-1). The results indicated that the number of bacteria, fungi, and actinomycetes in the 0-10 cm soil layer was significantly greater than that in the 10-20 cm layer. Nitrogen deposition did not change the original vertical distribution pattern of bacteria, fungi, and actinomycetes in the natural evergreen broadleaf forest in the Rainy Area of Western China. The L treatment did not have a significant effect on total soil microbial number, whereas the M and H treatments significantly reduced the total soil microbial number in both the 0-10 cm and 10-20 cm soil layers. Nitrogen deposition inhibited the number of bacteria in the 0-10 cm and 10-20 cm soil layers, and as nitrogen deposition increased, the inhibition effect was enhanced. Compared with the control, the M and H treatments significantly increased the number of fungi in the 10-20 cm soil layer during summer, indicating that a suitable amount of nitrogen deposition could effectively alleviate the nitrogen limitation of soil fungi in that season. Nitrogen deposition decreased the amount of fungi in the 0-10 cm soil layer, but there was no obvious relationship between the decrease and nitrogen deposition rate, whereas nitrogen deposition increased the number of actinomycetes in the 10-20 cm soil layer, and the increase was greatest in the M treatment. Nitrogen deposition first increased and then inhibited the number of actinomycetes in the 0-10 cm soil layer. The L and M treatments increased the number of actinomycetes, whereas the H treatment reduced the number of actinomycetes. The effects of nitrogen deposition on the quantity of soil microbial organisms decreased with increasing soil depth.