河口近海区域作为陆地与海洋生态系统的交汇点，其在氧化亚氮（nitrous oxide，N₂O）的生物地球化学循环中扮演着至关重要的角色。N₂O作为一种强效温室气体，其在河口近海的分布特征和微生物代谢驱动机制对全球气候变化具有显著影响。本文综述了河口近海区域N₂O的分布特征，N₂O释放的主要微生物代谢途径（硝化过程、硝化细菌反硝化过程、不完全反硝化过程、硝化作用耦合反硝化过程），N₂O产生与消耗过程的测定方法以及N₂O释放的环境影响因素。对河口近海N₂O生物地球化学循环的研究有助于我们制定有效的管理策略，减少N₂O排放，保护全球气候具有重要意义。

Estuarine and coastal waters, serving as the interface between terrestrial and marine ecosystems, play a pivotal role in the biogeochemical cycling of nitrous oxide (N₂O). The potent greenhouse gas has a profound impact on global climate change due to the distribution characteristics and microbial metabolic mechanisms of N₂O in estuarine and coastal waters. In this paper, we reviewed the distribution characteristics of N₂O in estuarine and coastal regions, the principal microbial metabolic pathways contributing to N₂O emissions, including nitrification, nitrifier denitrification, incomplete denitrification, and the coupling of nitrification with denitrification, as well as the methodologies for assessing N₂O production and consumption, and the environmental factors that influence N₂O emissions. Understanding the biogeochemical cycling of N₂O in estuarine and coastal waters is essential for devising effective management strategies to mitigate N₂O emissions, thereby protecting the global climate.