The purpose of the study was to analyze the characteristics of students' changing process during their study in a teachers' college. To achieve the purpose, a qualitative case study was carried out in a teachers' college. The results of the study were as followings: First, 'the alternating phenomenon' appeared on the students' changing process; students who had strong motivation for teaching at the entrance stage have eventually been weakened on their motive for teaching, whereas students who had low level of motivation at the early phase have been strengthened on their motive for teaching. Second, the causes of its appearance named as 'the alternating phenomenon' are as followings: 1) "the influence of curriculum at the teachers' college, 2) "the influence of teaching practice", 3) "the climate and atmosphere of the college, 4) "the positive attitude of students", and 5) "students' finding meaning in teaching job". From this research, some hints might be indicated for the elementary teacher education. It is strongly required to develop effective curriculum, strengthen teaching practice at teachers' colleges, and change the times and methods of students screening.