Based on the FAO-Penman-Monteith method, used the Hargreaves method, the Priestley-Taylor method, and the FAO-17Penman method, this paper calculated the reference crop evapotranspiration (ET0) of Urumqi in Xinjiang. The results were compared and analyzed, and different methods were revised. The results showed that (1) the seasonal distribution of ET0 is extremely uneven which has a decrease trend from summer,spring, autumn and winter successively; (2) in general, the estimated values of PT method and HG method are lower than the standard values of PM method, the values of F17are higher than the standard values of PM method,the main reason for the deviation is caused by different radiation and dynamic items in different methods; (3) when there is short of meteorological data or the precision demand is not very high, the PT method can be used to calculate the ET0 of Urumqi, if the precision demand is high, the revised PT method will be used to estimate the ET0; (4) the calculation result by the revised HG method is most consistent with the estimation by the standard PM method, and it must be revised before estimating ET0 for Urumqi by application of the HG method; (5) the F17method and the PM method adopts different revised schemes of wind velocity, witch results in a large deviation and unsuitable for ET0 estimation of Urumqi.