The increase of nitrogen deposition hadbecame a significant ecological factor effecting the material cycle in forest.We examined the effects of nitrogen deposition on soil enzyme activities in inorganic nitrogen addition and control plots in Larix gmelinii (Rupr.) Rupr.plantation,in northeast China.The experiment was divided into two treatment groups,one was control treatment (CK:0 kg·N·hm~(-2)·a~(-1)) and another was inorganic nitrogen treatment(IN:10 kg·N·hm~(-2)·a~(-1)).Each treatment included 3 replicate plots.Over 8 years of inorganic nitrogen addition,our results showed that N fertilization increased the activities of beta-1,4-glucosidase(BG),acid phosphatase (AP),and peroxidase (PER) (5.56%,8.66% and 0.61%) while reduced the activities of cellobiohydrolase(CBH),leucine aminopeptidase(LAP) and phenol oxidases(POX) (10.71%,3.85% and 12.30%).The long-term inorganic nitrogen addition treatment had a significant effect on soil enzyme activity and soil carbon,nitrogen and phosphorus cycles (0.80%,12.66% and-2.25%).Therefore,it is important to include the soil enzyme activity when studying the response of biogeochemical cycle and soil carbon dynamics to climate changein forest ecosystems in future research,while nitrogen deposition increases year by year.