Water samples collected from Prydz Bay and the adjacent Southern Ocean during the 25th and 26th Chinese National Antarctic Research Expeditions were analyzed for N 2 O concentration using the static headspace gas chro-matography method .The concentration of N 2 O over the Prydz Bay continental shelf was found to be relatively low , with a range of 13.2—17.4 nmol· L-1 , and it was undersaturated compared with the current atmospheric mixing ratio, with saturation anomaly centers at -7%.However, higher concentrations of N 2 O, with a range of 15.5—23.3 nmol· L-1 , were found in the adjacent Southern Ocean .The subsurface to bottom waters all showed oversatu-ration against the atmospheric mixing ratio prior to the industrial revolution .It was established that the distribution pattern of N 2 O within the study area was related to the complex hydrographic characteristics of the region .Prydz Bay shelf water with undersaturated N 2 O might mix with Circumpolar Deep Water and sink to the bottom of the Southern Ocean , forming Antarctic Bottom Water .This could act as a pathway for N 2 O transportation into deep wa-ter, providing a sink for atmospheric N 2 O.%利用中国第25、26次南极科学考察航次获得南极普里兹湾及邻近南大洋附近水样，采用顶空气相色谱法分析其中N2 O含量，结果表明普里兹湾陆架水体N2 O浓度较低，介于13．2―17．4 nmol· L－1，且呈现不饱和状态，饱和度异常值为－7％；而普里兹湾附近南大洋水体中N2 O浓度较高，介于15．5―23．3 nmol· L－1，除表面一层极薄的不饱和层外，中层至底层水体相对工业革命前大气浓度为高度过饱和状态。该区域N2 O的分布格局与复杂的水团特性和水文过程有密切关系。 N2 O含量不饱和的普里兹湾陆架水（ SW ）和绕极深层流（ CDW ）混合下沉形成南极底层水（ AABW），可能为温室气体N2 O提供向深层海洋输运的通路。这个过程为大气N2 O提供了一个汇的机制，使南极近岸水体成为大气N2 O的汇区。
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