The precipitation anomaly percentage series and air temperature anomaly series in each month and season over the Changjiang River source region are established, and the interannual change of air temperature, precipitation, and runoff is analyzed, based on the precipitation and air temperature data at eight meteorological stations and runoff data at the Zhimenda hydrological station over the Changjiang river source region. The result shows that the climate over the Changjiang River source region has a very significant interannual change. The precipitation amount was normal or greafer than normal in the 1960s and 1980s, and less than normal in the 1970s and 1990s, which attributed mainly to precipitation variation in summer. Annual air temperature has a rising trend, with the coldest period in the 1960s, warm autumns in the 1990s, and warm winters in the 1980s; the warming began from the 1970s and became fast after the 1990s. Presently, the annual, summer, autumn and winter temperatures are the highest since 1960s. The annual runoff corresponded to the interannual change and abrupt change years, greater than normal in the 1960s and 1980s, less than normal in the 1970s and 1990s. Except in spring, the runoffs in summer, autumn and winter start to rise at present, and there were abrupt changes in 1965, 1979 and 1997.