Abstract: The nitrogen distribution and release to the overlying water and interstitial water were probed into through a series of large static simulating experiments. The mass concentration profiles and vertical distribution of NH₄+-N, NO₂--N and NO₃--N were observed under different dissolved oxygen conditions and organic contents. It was found that different DO conditions strongly influenced the balance of the nitrification and de-nitrification; the mass concentrations of NH₄+-N, NO₂--N and NO₃--N are different in the interstitial water, water-solid interface and overlying water. DO condition contributes a little less to the NH+4-N and total nitrogen compounds release from sediments with high organic level than organic compounds content. But in sediments with low organic level, DO is more helpful than organic compounds.