The potential evaptranspirastion for vegetation should be calculated accurately before hydrologists design or operate a system of irrigation network or analyze water balance at a basin. As the evapotranspiration calculation of one area is different from another, because of the difference of climates each area, the variuos climates of each area must be calculated separately. Many calculation methods have developed, primarily fiom other country. However, those methods cannot be applied in Indonesia because of the difference of climatic condition. Experiments and adjustments are needed before they applied. This-research was started by calculating the rate of evaporation from pan-A then evpotranspimtion reference value calculated with chosen methods such as Penman modification, Radiation, Blaney-Criddle, Thorthwaite and Kananto Method which is applied in Java then statistical test used to obtain the nearest value of actual evapotranspiration. The result shows that the most appropriate method is Kananto Method. It is, thus, suggested that equation of reference evapotranspiration developed in overseas countries is better examined before it is applied in Indonesia or minimum compared with the equation has bezn applied in Indonesia.<\/p>\n