本文探讨了北海湾COD值的分布特征及其与水文、生物要素及不同形态氮、磷含量的关系 .结果表明 :河流输入对本湾COD值的影响突出表现在春、夏季 ,冬季最小 ,秋季则以沿岸排废、排污影响为主 ;水文要素对COD值的分布起主导控制作用 ,生物化学作用仅占次要地位 ;春、夏、冬三个季度月COD值与氮含量的相关性较为显著 ,秋季则与磷含量的相关性较为显著 This paper discussed the distribution characteristics of COD value and its relationship with hydrological and biological elements and nitrogen and phosphorus contents in the North Bay.The results showed that the impact of river input on the COD value of the Bay was outstanding in spring, summer and winter, while in autumn The discharge of pollutants along the coast and the impact of sewage were dominant. The hydrological factors dominated the distribution of COD values ​​and the biochemical effects only took a secondary position. The correlation between COD values ​​and nitrogen contents in spring, summer and winter was significant , While the correlation between phosphorus content in autumn is more significant