Nitrogen will influence the biomass production as the most commonly growth-limiting nutrient in forests.Nowadays, more and more nitrogen deposition gradually attracts attention, by consequence for effecting climate quality and nitrogen cycle by water flows. In this study, hydrological cycle (bulk precipitation, throughfall, stemflow, litter leachate, soil solution and stream water) and internal nitrogen cycle were investigated in a cool-temperate broad-leaved deciduous forest in central Japan, to estimate the fate of nitrogen deposition and characteristic of internal nitrogen cycle. Nitrogen deposition rate was 10 kg N ha^–1yr^–1, which was consistent with that reported in Europe and Japan, but extremely lower than that in Chinese forests induced by more human activity. There were forest canopy effects on dynamics of dissolved organic nitrogen (DON) and dissolved inorganic nitrogen (DIN). Significant interspecific difference of DON concentration in stemflow was found in this study site with higher concentration of DON in stemflow of Quercus. The variations of concentrations of DON in litter leachate showed clear seasonal pattern with two peaks (August and November), maybe related to the amount of litter fall and soil temperature. In internal nitrogen cycle, Takayama forest demand 88.9 kg N ha^–1yr^–1, litter leachate contributed 5.7%, mineralization in 0–5 cm contributed 20.4% and resorption by tree contributed about half of nitrogen demand. Nitrogen could be neglected because of no significant difference among the concentrations of dissolved nitrogen in bulk precipitation, stream water and each depths of soil solution.