The meteorological data of the Zoige, Hongyuan and Maqu weather observation stations were used, the potential evapotranspiration was computed by using Penman-Monteith model. The results indicated that the potential evapotranspiration variation in the Zoige wetland shows an obvious increasing tendency with the tendency ratio of 9.1 mm/10a,An abrupt change of the potential evapotranspiration was detected in the 2001, the mean potential evapotranspiration during 2001-2010 has increased by 28.6 mm compared with that of 1971-2000. The autumn potential evapotranspiration increased with the tendency ratio of 4.3mm/10a,its more higher than the other seasons. The annual potential evapotranspirations minimum period is 1980s, it obviously increased from 1990s, the variety of seasonal potential evapotranspiration in spring, summer and autumn is very similar to that of annual. The winter potential evapotranspiration minimum period is 1990s, it obviously increased in the 21st.The cycle change is 7-8 a during 1970s and 1980s, from the end of 1980s to the end of 1990s, it is an obviously adjusted period, the cycle change is 5a from the beginning of 21st. The temperature rising, relative humidity and precipitation decreasing are the major contributors to the potential evapotranspiration increased. Although the decreasing of the sunshine duration and mean wind velocity is help to the potential evapotranspiration decreased, but the temperature rising plays a more important role to the potential evapotranspiration increased. The decreasing tendency of soil surface humidity index is -0.03/10a,the soil surface humidity index has decreased 0.11 during 2001-2010 compared with that of 1981-1990. meanwhile, the increasing tendency of the mean temperature is 0.41℃/10a, the decreasing tendency of the precipitation is -13.5 mm/10a, the climate change of the Zoige wetland shows an obviously warm-drying tendency.