Abstract: In order to understand the nitrogen mineralization characteristics of poplar plantation soil in different temperature and moisture conditions, especially under drought condition, the author used laboratory incubation method, incubated poplar plantation topsoil from 0-10 cm layer of three soil moisture 20% (severe drought), 40% (mild drought) and 70% (control) of field moisture capacity for 8 weeks at 15, 20, 25 and , respectively. The results showed that:(1) the net nitrogen mineralization accumulation of soil was positively related to temperature (P<0.01); (2) at 15 and , the net nitrogen mineralization accumulation of soil in different moisture showed the order of mild drought>severe drought>control treatment; at 25 and , the sequence was the same as that at 15 and in early incubation, while the order was control>mild drought>severe drought in the subsequent incubation time; (3) the net nitrogen mineralization accumulation was mainly nitrate nitrogen in the soil; (4) soil electrical conductivity was significantly positively related to soil nitrate nitrogen and net nitrogen mineralization accumulation (P<0.01). It was suggested that slight drought condition was conducive to soil nitrogen mineralization in the early incubation period, however, the appropriate moisture condition could promote soil nitrogen mineralization in the long-term incubation period.