This dataset supports research on how forest productivity in temperate forests of Northeast China responds to atmospheric nitrogen deposition. It comprises survey data from 396 circular forest plots (0.1 ha each). The dataset includes the region of each plot, geographic coordinates (longitude and latitude), atmospheric nitrogen deposition (N_dep), climate variables (annual mean temperature, annual precipitation, precipitation of the driest month, precipitation seasonality, and precipitation of the driest quarter), soil properties (soil sand content and cation exchange capacity at pH 7), multiple biodiversity metrics (tree species diversity, tree phylogenetic diversity, tree functional diversity, and functional identity), and forest biomass productivity (TP). These data were used to examine the effects and pathways through which atmospheric nitrogen deposition, biodiversity, and climate influence forest productivity, as well as to analyze the relationship between nitrogen deposition and productivity along biotic and climatic gradients. Overall, the dataset provides new insights into patterns of temperate forest productivity responses to atmospheric nitrogen deposition under specific ecological and climatic contexts.