Sediment discharge from the Yangtze into the sea has decreased rapidly from 481.7 × 10⁶ tons/y (1953–76) to 389.5 × 10⁶ tons/y (1977–2000), without any corresponding decrease in water discharge. In 2001, the sediment discharge from the Yangtze dropped to 276 × 10⁶ tons. Human activities and climate changes obviously play a major role for reducing the sediment supply from the upper basin and for increasing the sediment sinks in the mid–lower basin. Sediment budgets in different parts of the Yangtze are estimated according to hydrometric data and other sources. Major physical and anthropogenic processes are examined with respect to their effects on sediment discharge from the Yangtze into the sea. The decrease of sediment supply (−46.8 × 10⁶ tons/y) from the upper Yangtze in the second period accounts for about 50% of the total decrease (−92.2 × 10⁶ tons/y) into the sea, mostly due to the increased sedimentation in reservoirs as well as climatic factors. The other 50% decrease is mostly attributed to increased sand mining in the mid–lower Yangtze and the decreased sediment supply from the Hanjiang River after building the Danjiangkou Reservoir.