The topic of my PhD research is “Nutrient export by rivers to the coastal waters of China: an integrated sub-basin modelling approach”. Coastal waters of China have been experience eutrophication and harmful algal blooms since the 1970s. The main reasons of these problems are excess of nutrients such as nitrogen (N) and phosphorus (P) in the coastal waters. Rivers transport considerable amounts of these nutrients to the Chinese coastal waters. This is a result of human activities namely agriculture and urbanisation. An integrated sub-basin modelling approach have been developed to understand better the main sources of nutrients in rivers and locations of these sources within large basins in China (e.g., Yangtze, Pearl, Yellow basins) in the past and future. For example, two-thirds of dissolved inorganic N and P inputs to the South China Sea arrive from down-stream areas of the Pearl River basin, where agriculture and urbanisation are intensive. This indicates that nutrient management in down-stream areas is likely more effective in reducing coastal eutrophication than in up- and middle-stream areas of the basin. These modelling results may help policy-makers to formulate management options to reduce river export of nutrients and thus coastal eutrophication in the coming years.