Summary 1. Research has indicated that increases in nitrogen (N) deposition can greatly affect ecosystem processes and functions. There is limited information about the effects of long-term N addition on soil nematodes and their functional composition, although nematodes are the most abundant multicellular animals on Earth. 2. We conducted a field experiment in 2004 with four levels of N addition (0, 60, 120, and 240 kg N ha-1 yr-1) in a subtropical Cunninghamia lanceolata forest. Soil samples with three depths (0-20, 20-40 and 40-60 cm) were collected and the community structure, diversity and trophic groups of soil nematodes were determined in 2014. 3. N addition significantly increased the abundance of bacterial- and fungal-feeding nematodes, but decreased the abundance of plant-feeding nematodes at the 0-20 cm soil layer. Accordingly, the plant parasite index and enrichment index decreased but the basal index and channel index increased, which weaken the importance of the plant-based energy channel, but enhance the importance of the fungal-based energy channel. N addition had no effects on the diversity of soil nematodes in three soil depths. Structural equation modeling analysis indicated that N loading directly changed plant-feeding (total r2=0.42) nematodes, or indirectly affected bacterial- (r2=0.43), fungal- (r2=0.31) and plant-feeding nematodes via change soil nutrients, soil water content and pH. 4. These findings suggest that N addition can change the community structure and energy channels soil nematodes, which would affect soil processes and food web functions in forest soils under future environmental change scenarios.