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于2006年6月和2007年4月在长江口及毗邻海区采集了表层沉积物样品,利用水淘选法对沉积物进行了粒径分级,并采用改进后的SEDEX方法对沉积物样品及分粒级沉积物样品进行了磷形态分析.结果表明,2006年6月和2007年4月长江口及毗邻海区沉积物总磷变化分别为12.56～19.64μmol/g和8.99～19.91 μmol/g,其中碎屑磷是磷的主要存在形态.可交换态磷、铁结合态磷、有机磷、自生磷灰石磷及难分解有机磷在长江口外的平面分布比较一致,均在紧邻长江口门外、杭州湾外的条状带出现了含量的高值,而在口门内及口门外河口靠海一侧碎屑磷含量较高.不同形态磷在不同粒径沉积物中的含量不尽相同:有机磷、自生磷灰石磷以及难分解有机磷是小于8μm粒级沉积物中磷的主要组成部分,而且其在总磷中所占比例随沉积物粒径的增加而下降;碎屑磷则主要集中在粗沉积物中,为32～63 μm及大于63μm粒级沉积物中磷的主要贡献者.沉积物的粒度分异以及各形态磷在不同粒径沉积物中含量的差异,共同影响着河口沉积物中磷的分布.“,”Surface sediments were collected from Changjiang Estuary and its adjacent sea in June 2006 and April 2007. The sediments were separated into five fractions via water elutriation. The sediments and the fractioned sediments were analyzed with modified SEDEX to obtain six forms of phosphorus. The results indicated that TP in June 2006 and in April 2007 varied from 12.56 to 19.64 μmol/g and from 8.99 to 19.91 μmol/g, respectively. Detrital P was the major form. Exchangeable P, iron bound P, organic P, Authigenic P and refractory P had the similar distribution pattern with higher contents appeared just out of the Changjiang Estuary and Hangzhou Bay, while higer detrital P content was found in the lower estuary. The content of different P forms varied by sediments size: organic P, Authigenic P and refractory P were the dominant forms in 63 μm classes. The distributions of P in estuarine sediments were affected mainly by the sediments size and the content of various particulate P in different particle size classes.