Abstract:[Objective] The dynamic pattern of soil enzyme activities and its relationship with soil chemical properties in a subtropical Pinus armandii forest was investigated to provide reference for the study of nitrogen deposition in subtropical regions. [Methods] Four nitrogen gradient treatments for the control (CK) and low (LN), medium (MN), and high nitrogen (HN) at 0, 10, 20 and 25 g/(m2·a), respectively, were set up in the subtropical Pinus armandii forest of Central Yunnan to analyse the response of soil enzymes to nitrogen deposition and its correlation with soil chemical properties. [Results] ① Nitrogen deposition promoted the activities of invertase (16.94%—34.00%) and acid phosphatase (23.42%—40.09%) and inhibited the activities of urease (8.70%—27.18%) and catalase (9.26%—23.36%), with temporal variation (p<0.05). Invertase and urease activities were highest at 25th and 27th month after nitrogen deposition (August and October, 2021), whereas acid phosphatase and catalase activities were highest at 33th month after nitrogen deposition (June, 2022). ② Soil pH value, organic carbon, and total phosphorus content decreased with increasing nitrogen deposition; in contrary, soil nitrate and ammonia nitrogen content increased in MN and decreased in HN. ③ Soil chemical properties and enzyme activities were characterized by a vertical soil layer distribution of 0—5 cm >5—10 cm >10—20 cm. The synergism between different soil enzyme activities under nitrogen deposition was high (p<0.05), among the environmental factors affecting soil enzyme activities, soil total nitrogen was the most sensitive factor affecting invertase activity; soil organic carbon, total phosphorus, and ammoniacal nitrogen were the most sensitive factors affecting urease and catalase activities. [Conclusion] With continuously increase in nitrogen deposition, the synergism among soil enzymes was enhanced, the environmental factors affecting forest soil were changed, the soil enzyme activity was promoted or inhibited, and then the soil nutrient cycling was changed too.