The purpose of this study is to take a close look at team teaching between a Korean elementary English teacher and a native teacher of English and thus to explore ways that team teaching can be performed more effectively. The data consists of teaching journals and an interview. Teaching journals were written by the Korean teacher and the native teacher for one semester while co-teaching. The analysis of data revealed the followings. First, the role relationships between the two teachers changed dynamically as the native teacher had more experiences of teaching. The native teacher was a novice at first, but she became the associate and sometimes team leader in the end of the semester. Second, the Korean teacher's efforts to communicate with the native teacher regarding the contents and methods of teaching helped the native teacher progress in teaching skills and management of class. Third, the Korean teacher felt stress due to too much work and responsibility related to team teaching although she found the experience of team teaching rewarding in terms of her professional development. Finally, it was found that activities and games rather than reading and writing were more appropriate for team teaching. Based on these findings several suggestions were made.