Studying the temporal and spatial variations of potential evapotranspiration ET0 and its response to climate change in Longdong region is helpful to understand the effects of climate change on hydrological processes. Based on the meteorological data from 1984 to 2019 in Longdong region, the spatial and temporal variation characteristics of ET0 were revealed by statistical and spatial interpolation methods. The relationship between ET0 and meteorological factors, as well as the sensitivity and contribution of ET0 to the changes of meteorological factors were discussed by combining qualitative and quantitative analysis methods. The results show that ET0 in Longdong region presents a significant upward trend, with a linear change rate of 3. 03 mm / a, and a sudden change occurred in 1993. Principal component analysis shows that meteorological factors such as temperature, humidity, radiation and power all have an impact on ET0 , with temperature having the greatest impact and power having the least impact. Path analysis results show that daily maximum temperature Tmax and sunshine duration n are the most important factors affecting the change of ET0 , followed by relative humidity RH and average wind speed u, and rainfall P has the least influence on the change of ET0 . The sensitivity of ET0 to the change of meteorological factors is ranked as RH, Tmax , n, u. RH has a reverse effect, and the decrease of RH has the greatest effect on the increase of ET0 . Tmax , n, u have a positive effect, and the increase of Tmax , n, u over the years promotes the increase of ET0 . The main reason for the increase of ET0 is the increase of Tmax , followed by RH and u, and n contributes the least to the increase of ET0 . The total contribution of the four meteorological factors is 24. 65% .