This study examines the state changes of nutrients (nitrogen, phosphorus and silicon) from one of the ten largest river systems in the world, the Changjiang, based on field expeditions and time-series data since early 1980s. The study covers an area of ~80% of the whole drainage basin (i.e., 1.8×106 km2) and 70% of water course, including main streams and 15 major tributaries.