"The purpose of this study was to explore mutual reaction characteristics and role understanding using the U-learning in elementary pre-service teacher education between instructor and learner. This study was performed from September 2009 to June 2010 and was designed as a qualitative case study and then was analyzed in interpretive perspective. This study was performed at C university of education in K province. The subjects were six students(3 males, 3 females) who took elementary physical education class I and professors who taught the class. The data were collected from many different sources such as professor's diary, student interviews, classroom materials and handouts. The results of this study in students' perceptions and experiences were categorized as 1) the smell of different ideas: a series of reflection and intellectual conflicts, 2) the naked emperor: expose myself free, 3) praise the power of whales to dance: building self-esteem for 'I' , and 4) a journey to find myself: what I know/ what I do not know. The results of this study in professors' perceptions and experiences were categorized as 1) race against time: trying filling the water in broken jar and 2) the fruit of pride: I am professor.
※ Key words : Computer-mediated communication, U-learning, elementary pre-service teacher education"