To promote interdisciplinary studies in marine environmental science and to foster the next generation of ocean scientists, the State Key Laboratory of Marine Environmental Science (MEL), Xiamen University, initiated the Xiamen Symposium on Marine Environmental Sciences (XMAS) in 2014. The symposium has since grown into one of the largest international conferences in marine sciences in Asia, providing an important platform for the exchange of research advances and scientific ideas related to global and regional oceans.

XMAS 2027 will be held in Xiamen, China, from January 12 to 15, 2027, and is jointly organized by the State Key Laboratory of Marine Environmental Science (MEL), Xiamen University, and the Department of Earth Sciences, National Natural Science Foundation of China (NSFC). XMAS 2027 will feature interdisciplinary, cutting-edge sessions covering physical, chemical, and biological oceanography, marine pollution, as well as marine policy and management. In addition, a range of workshops and special sessions focusing on emerging topics in marine environmental sciences will be offered, including ocean-based carbon removal, ocean governance and sustainability, the marine economy, marine education and outreach, as well as dedicated sessions on Women in Science and mentoring future scientists. These activities will bring together leading experts and early-career researchers from around the world.

Established in 2005 under the sponsorship of the Ministry of Science and Technology of China (MOST), the State Key Laboratory of Marine Environmental Science (MEL) has been awarded the title of Excellent State Key Laboratory in two consecutive official reviews by MOST. MEL is committed to interdisciplinary, cutting-edge research in marine environmental sciences, with particular strengths in marine biogeochemistry and ecosystem studies.

Originally known as Amoy, Xiamen is a coastal city renowned for its rich cultural heritage, pleasant climate, and beautiful natural scenery. Located on the southeast coast of China, Xiamen has a long history of international exchange and maritime commerce. The city has received the United Nations Habitat Scroll of Honor Award and has been recognized as an International Garden City and a National Model City for Environmental Protection. Its clean and well-maintained environment, courteous citizens, and harmonious blend of natural and urban landscapes contribute to a calm, livable, and welcoming atmosphere. Xiamen has a monsoonal humid subtropical climate, characterized by mild and relatively dry winters, with an average temperature of around 15 °C (59 °F) in January.