In order to study the spatio-temporal pattern of potential evapotranspiration (ET0) in Jialing River Basin (JRB) and the influence of changing climate conditions on potential ET0 in the basin, the daily meteorological data from 1970 to 2019 were collected from 45 national meteorological stations in JRB for the calculation of ET0. The spatio-temporal variation characteristics were analyzed by linear trend rate, Mann-Kendall trend test and inverse distance weighted (IDW) interpolation. The sensitivity analysis and contribution rate were used to quantify the leading factors influencing the change of ET0, and the interactions between the influencing factors were analyzed by the geographic detector. The results show that at the annual scale, the mean air temperature in the JRB increased at the rate of 0.20 ℃/10a, while the relative humidity, average wind speed and sunshine duration decreased at the rates of 0.239%/10a, 0.048 (m·s-1)/10a and 0.10 (h·d-1）/10a, respectively. Moreover, the annual ET0 decreased at the rate of 0.133 mm/10a, which increased in spring and winter, but decreased in summer and autumn. Spatially, annual ET0 was higher in the north but lower in the south. In conclusion, the leading factor of annual ET0 change was mean air temperature; however, the change of ET0 in JRB was the result of the interactions of multiple factors, and the explanatory power of the interaction between mean air temperature and relative humidity reached 68.4%. The results can help understand the deep analysis of ecological and hydrological processes in the study area.