Abstract: Based on the daily meteorological data from 116 meteorological stations in the Yangtze River basin of China in 1961-2011, and by using the Penman-Monteith method recommended by the FAO, this paper calculated the potential evapotranspiration in the basin. In the meantime, the methods of inverse distanceweighted interpolation, MannKendall mutation test, Morlet wavelet analysis, and rescaled range analysis were adopted to study the spatiotemporal variation patterns of the potential evapotranspiration. In recent 51 years, the inter-annual change tendency rate of the potential evapotranspiration in the whole basin was -0.34 mm·a^-1. Spatially, the potential evapotranspiration had an increased  trend  after an initial decrease from west to east. Temporally, the potential evapotranspiration presented an obvious increasing trend in autumn, but a decreasing trend in spring, summer, and winter, with an overall tendency of summer > autumn > spring > winter. The M-K mutation test and Morlet wavelet analysis showed that the yearly potential evapotranspiration mutation happened around 1980, and the departure sequence vibration of the potential evapotranspiration frequency was primary quasi 12 years and secondary quasi 4 years. The rescaled range analysis showed that except precipitation, all the test climate factors had the same variation trend with the potential evapotranspiration as that in the past.

Key words: indicators of hydrological alteration (IHA), eco-hydrology, change of water regime, the Three Gorges Reservoir, three outfalls of Chingjiang River.