Abstract: The paper aims to calculate sensitive coefficient of various meteorological elements on potential evapotranspiration, with the daily observations from January 1, 1961 to December 31, 2012, by adding Gauss distributed random disturbance. Research showed that: on the year scale in Anhui Area, the sunshine duration and the average wind speed were the highest sensitive factors, sensitive coefficients were 0.1258 and 0.1089. On the month scale, the main sensitive factor from April to September was the sunshine duration, the main sensitive factors from October to March were the average wind speed and the actual water vapor pressure. The sensitivity of spatial distribution was uneven. The sunshine duration was the main sensitive factor for the south area of Huaihe, the average wind speed was the main sensitive factor for the north area of Huaihe.