n 1989, Shlomo Vinner and Tommy Dreyfus (Vinner. S and Drey 舡. T, 1989) investigated 271 college students of different majors and 36 teachers of junior high schools in Israel on their understanding of the concept of function. The results showed that the students' understanding of the concept of function was diverse, and the contradiction between the appearance and definition of the concept of function was very common. The survey shows that students of different majors have different understanding of the concept of function. Except for the students and teachers of mathematics major, students of other majors have superficial and simple understanding of the definition of function. The proportion of students who can give the correct definition and narration increases with the improvement of their mathematics level.