Nitrogen mineralization was evaluated in four forest communities in Hunan, which were Camphor community, Masson Pine community, Sweetgum community, and Chinese Fir community. The resin-core technique was employed to determining net mineralization rates under field conditions. The N mineralization was analyzed before and after 28d. The results indicated that the ammonia nitrogen and nitrate nitrogen were 8.63-20.5 mg·kg-1 and 0.27-0.64 mg·kg-1 before the experiment, respectively. After 28d incubation, ammonia nitrogen decreased 31.4%-50.5% and nitrate nitrogen increased 8.2-17.3 times among four forest communities. Net N mineralization rates was significantly different among those communities, the highest rate was measured in camphor communities (0.05mg·kg-1·d-1) and the lowest rate in Chinese Fir communities（-0.15 mg·kg-1·d-1）. The ammonia nitrogen accounted for 78.42%, 79.17%, 71.14% and 79.22% of the inorganic nitrogen in Chinese Fir, Masson Pine, Camphor and Sweetgum communities, respectively. Ammonia nitrogen contributed 96.1%-98.8% N mineralization. The net nitrogen mineralization rate was significantly correlated with soil C/N ratio and pH value in 0-15cm soil layer and no significant correlations was found with litter and fine root in 0-30cm soil layer of all forest communities.