Abstract: In order to control under the background of climate warming changes in air temperature and evaporation in Yuanyang County Meteorological Bureau, the 1971 monthly in 2009 20 cm pan evaporation, the monthly mean temperature data, the author analyzed the amount of time and temperature in Yuanyang County evaporation variation. The results showed that: (1) the temperature the overall upward trend, from 1971 to 2009 during the last 40 years the average temperature had increased by about 0.4℃. 1970s slowly rising, 1980s into decline, 1990s after the warming trended to accelerate. On the season, spring, autumn and winter temperature change tendency rate was positive, respectively was 0.51℃/10 a, 0.10℃/10 a, 0.34℃/10 a. Winter warming was most obvious, in spring, but the tendency of summer rate was negative (-0.09℃/10 a). (2) The annual evaporation decreased, climate tendency rate was -153.4 mm/10 a. Among them, slowly decreased 1970s, 1980s decreased obviously, after 1990s rose, since 2001, also showing a downward trend. Analysis of seasonal changes could be seen: in spring and summer down trend was most obvious, climate tendency rate were 53.9 mm/10 a and 56.7 mm/10 a, autumn, winter was not too obvious. The cumulative anomaly of annual mean temperature and annual evaporation mutation analysis, discovered in 1983, 1993 as the temperature mutation. Among them, the 1993 mutation was the most significant, the cold period to warm period. 1986 was for evaporation mutation, evaporation from partial multi period to less periods.