Nitrogen deposition is one of the major environmental factors affecting the biogeochemical cycles of terrestrial biogenic elements. The increase of nitrogen deposition may increase the carbon storage in the litter and soil. In this study, earthworm species and density were investigated by hand picking method and square soil sampler in a mixed broad-leaf Korean pine forest in Changbai Mountain, China after 6 years of N addition (ambient+N50 kg·hm~(-2)·a~(-1)) treatment. Meanwhile, litter and soil layer of organic carbon and nitrogen content were determined by an element analyzer. The results of the study showed that in control and nitrogen addition plots, earthworm species and density distribution pattern was similar. The 4 species of earthworms were observed. Eiseniafoetida and Pheretima sp. were epigeics. Drawidachangbaiensis was endogeics and anecics. Enchytraeidae spp. was earthwomenchytraeidae larvae. Among them, the density of Eiseniafoetida was the largest, and it could reach 25 individuals·m~(-2). The density of Drawidachangbaiensis was 6 individuals·m~(-2), and the density of Pheretima sp. was smallest. The total density of three functional groups was 23 individuals·m~(-2) in the control plots and 31 individuals·m~(-2) in the nitrogen plots, respectively. Thus, there were no significant differences (P=0.238) in the species and density of earthworms in control and nitrogen addition plots in Changbai Mountain. In the four layers of litter and soil, the total carbon was not affected by nitrogen addition, and total nitrogen was not significantly changed. The results improve our ability to estimate carbon sequestration potential of forest soil and build a global carbon cycle model under future climate change especially elevated N deposition.