Taking the subtropical moso bamboo (Phyllostachys edulis) forest as research object, the soil biochemical properties and enzymes activities were studied using two forms (NH₄Cl and KNO₃) and three levels (0,40 and 120 kg / (hm²·a).The results showed that: (1) The nitrogen input reduces the pH of soil, different forms and levels had a significant effect on soil pH (P=0.001 and P=0.010); (2) Under high nitrogen treatment, nitrate nitrogen of soil NH₄⁺-N、NO₃^--N and DON differ with ammonium nitrogen of 12.33%, 40.06% and 50.10%. Under the same nitrogen form, high-N treatment of soil NH₄⁺-N、NO₃^--N and DON differ with ammonium nitrogen of 24.24%, 47.12% and 78.12%. Nitrogen forms and levels had significant effects on soil biochemical properties; (3) Compared with the CK, soil urease and invertase activities were increased by 14.16% and 8.11% under High-N treatment, and nitrogen forms had no significant effect on soil urease and invertase activities. Nitrogen levels and forms had no effect on catalase activity (P>0.05); (4) Soil enzyme activities (urease, inverse and catalase activities) showed significant seasonal variation in bamboo forest. The highest activities of urease and invertase were found in the summer and the lowest activities of urease and invertase were found in the winter. But the highest activities of catalase activity was found in the winter. However, inputs of extraneous N made little different on temporal variation. Through the Pearson method, Soil enzyme activities were significantly correlated with soil biochemical properties (P<0.05). The above results show that the effects of nitrogen levels and forms on soil biochemical properties and enzyme activities are different, which can provide a theoretical basis for the management of subtropical moso bamboo (Phyllostachys edulis) forest under the background of nitrogen deposition.