To fit the needs of marine environment observation and research in China and Guangdong under the carbon neutralization policy, we will build a pilot buoy array in the Pearl River Estuary towards monitoring air-sea CO2 flux and carbonate chemistry. The marine environment observation and carbon neutralization demonstration platform will have local contents of more than 70%, so as to support the regional sustainable development and to achieve the national carbon neutralization goal. We will also repeat carbonate chemistry observation along several typical sections radiating the South China Sea and the Western Pacific. Based on high-quality field data and simplified modeling, we will study the variations of carbonate parameters in the Western Pacific and their interactions with carbon source/sink items in China marginal seas.