The present study aimed the evaluation and zoning the evapotranspiration based on mass transfer methods in different climates of Iran and presented it in the form of zoning maps as a basic tool for water management. For this purpose, the long-term means of climate variables were used for 150 synoptic stations in Iran during 15-years of statistical period (1990 to 2013). De Martonne method was used for climate zoning in different parts of the country. The results of the study showed that dry, semi-arid, Mediterranean, semi-humid, moist, and very humid climates were covering 75. 7, 21, 0. 8, 0. 6, 0. 8 and 1% of the country's land area. Evapotranspiration of the reference plant was calculated based on the climatic information of each station using the methods of mass transfer including Dalton, Trabert, Meyer, Rohwer, Penman, Albrecht, Romanenko, Brockamp and Wenner, World Meteorological Organization, and Mahringer. The most appropriate and inappropriate computational methods in each climate were selected among the abovementioned methods, compared to the FAO-Penman-Monteith equation as a reference method. Based on the calculations and statistical analysis conducted for dry climates by the World Meteorological Organization and Albert, the semi-dry methods of the Meyer and Romanenko, Mediterranean methods of the World Meteorological Organization and Albert, the semi-wet and wet methods of Rohwer and Romanenko methods the very humid methods of Brockamp and Wenner and Penman were chosen as the most appropriate and inappropriate methods respectively. Meanwhile, the resulting lysimetric data confirmed the selection of suggested methods in a semi-arid climate.