Xiangjiang River is the largest tributary in Dongting Lake Basin,knowledge of the water and sediment discharge and their underlying impacting factors is essential for the security of water resources and ecological environment protection in Dongting Lake Basin,especially under the conditions of global warming and intensive human activities.This study analyzed the changing patterns of water and sediment discharge,climate aridity[based on the self-calibrating Palmer Drought Severity Index(sc-PDSI)and the 12 month scale Standardized Precipitation Evapotranspiration Index (SPEI-12)],vegetation coverage (based on NDVI),and precipitation(based on the five indices of precipitation amount(R),rainfall intensity(R_i),max 1-day precipitation amount(R_(x1))and max 5-day precipitation amount(R_(x5)),and investigated the underlying factors for the relationship between water and sediment discharge in Xiangjiang Basin,by using MK trend,MK abrupt change test and correlation analysis.The results showed that the obvious declining precipitation,increasing sc-PDSI and SPEI-12 and precipitation intensity and increasing NDVI were observed in Xiangjiang Basin in the past decades.The trend of runoff was similar to that of precipitation(R)and climate aridity(sc-PDSI and SPEI-12).However,the sediment discharge significantly decreased during the period from1982 to 2011.The reasonable explanation for the decline in 19912002 and 20032011,might be the water conservancy projects construction and the integrative effects ofGrain for Green'Project,respectively.