The representativeness of evaporimeters in enid area has been questioned by using Grey Incidence Method in this paper.The analysis was carried out with the periodic (Apr.-Oct., 1984-1986) observing data of evaporation capacities by different evaporimeters in arid areas as Hadipo Station and Aksu Station, which lie in the northern and southern slopes of the Tianshan Mountains in Xinjiang separately.The evaporimeters include different types such as ф20 cm,E-601,ГГП-3000,20 m² and A class.The monthly evaporation capacity of 20 m² evaporipool has been considered as standard evaporation .It is assumed that the relations between evaporation capacities by using 20 m² evaporipool and other evaporimeters such as ГГП-3000,E-601,ф20_-3 cm,ф20_-2 cm,A class are r₁,r₂,r₃,r₄,r₅ respectively.The orders of grey incidence degree are r₄ >r₁ >r₃ > r₂ in Hadipo Station and r₁ >r₂ >r₃ > r₅ in Aksu Station.In the meantime,the linear correlation analysis shows that correlation coefficients are in the order of Hadipo Station and r₂ >r₁ >r₅ >r₃ in Aksu Station.Obviously,the order of incidence degree differs from that of correlation coefficient.The preliminary analysis gives the following reasons for the difference: (1) the grey incidence degree focuses on the consistency of procedure while the correlation coefficient on the correlating degree between two series;(2) that two series are almost stable and normally distributed is the prerequisite for the caclulation of correlation coefficient, while the caclulation degree has nothing to do with series Stability and distribution.The above analysis advances a question on the ever-established conclusion that the monthly evaporation of evaporimeter E-601 represents that of large evaporipool in arid area.What type of evaporimeters can represent the evaporation of physical water body still awaits further discussion.