Soil nitrogen mineralization is the process of organic nitrogen is converted into plant-useable inorganic nitrogen forms by soil microorganisms. As a volcanic island, Miyakejima island was erupted in 2000, deposition of volcanic ash and poisonous gas caused a severe damage for vegetation and soil. After the eruption, damaged ecosystems are in process of restoration succession in Miyakejima island. The present study aim to estimate annual nitrogen mineralization rate (NMR) in soil and to examine key environmental factors for NMR. We measured annual NMR in soil by using resin core method at 11 sites showing varying degree of damage in the island from August 2013 to August 2014. We monitored soil temperature and soil water content during the period. We analyzed organic matter content (SOM), carbon (C) and nitrogen (N) concentration in soil which obtained at the end of the period. These results showed that the range of annual NMR among 11 sites were -12.19 mg N• kg-1•yr to 177.35 mg N• kg-1•yr. The annual net NMR was significant correlated with SOM, soil total C, N content.