Abstract: The dynamic changes on the soluble nitrogen pool and nitrogen metabolism enzymes in soil as the environmental temperature was altered in a humidity-controlled incubation chamber were studied. The results showed that (a) the NO₃^--N in soil increased within 58 d after cultivation, and peaked between 48^th and 58^th d followed by a continuous decline; while NH₄⁺-N decreased initially and stabilized after 73 d, and SON fluctuated with a maximum on the 48^th d; (b) NO₃^--N increased upon increasing temperature with a significant correlation, but NH₄⁺-N had an opposite trend with a significant inverse correlation with the temperature; whereas, SON significantly correlated with the increasing temperature only in the mid-and late-stages; and, (c) the urease activity fluctuated during the entire incubation; the protease activity was higher in the initial and mid-than the late stage; the activity of asparagine enzyme increased initially but declined afterward, while that of the glutaminase enzyme increased continuously in the course of the test; and, within the testing range, the temperature induced little effect on the urease activity, but significantly affected the protease, asparaginase and glutaminase in a certain sampling times.