FAO56-Penman-Monteith?(?FAO-PM?) method, distance?average?analysis, regression?analysis?and?geographical?information?technology?were?adopted?to?analyze?temporal?characteristics?of?reference?crop?evapotranspiration?(?ET0?)?in?Pu'er?City?in?three?time?scale the?decadal,?inter-annual?and annual, by using daily meteorological?data?from 1959?to?2017 provided by?Pu'er?City?Surface Meteorological?Observatory. The results show that the average ET0 age in Pu'er City was the largest in 2011 to 2017, with a maximum of 1 196.2 mm, the smallest in 1959 to 1960, and the minimum value was 1 101.0 mm. The ET0 mean high value area was on the south side of the western part of Pu'er City, and the low value area was on the north side of Ximeng in the west of Pu'er City, north of Jingdong in the north and the eastern edge of Jiangcheng in the southeast. The interannual variability of ET0 in all meteorological stations in Pu'er City showed a volatility trend. The annual volatility of the average ET0 value of Ximeng Station is the largest, and the annual volatility of ET0 of Jiangcheng Station is the smallest. The spatial distribution of the annual average ET0 annual value: Jingdong, Jiangcheng, and the northwest region are smaller, and the south of Menglian and the south of Lancang stations are larger. The average ET0 season of each station is the largest in spring, followed by summer, and gradually decreased in autumn and winter. The trend of the monthly average ET0 of each station is basically the same, the curves were bimodal, the highest peak appears in April and May, and the second peak appears in August and September.