The environmental quality of Guangzhou sea area was assessed using water quality data from 2003 to 2004. Key pollutants like nitrogen, phosphorus, oil, copper, and lead were found in high concentrations, with nitrogen being the most concerning. Pollution levels were highest in inner bay areas and nearshore locations, gradually decreasing towards outer bay and offshore areas. The overall water quality index and eutrophication index were higher in inner bay and nearshore regions compared to outer bay and offshore areas. The study indicates that Guangzhou sea area is significantly polluted, mainly due to land-based pollutants and the flow of water from the Pearl River.