This study aims to investigate how some Korean primary school students practiced autonomous English-learning while they exchanged email letters with foreign friends for 20 weeks. In order to achieve triangulation of the study, the following data resources were used: email letters exchanged and uploaded at an Internet cafe, a survey implemented in April and July as an autonomy measuring instrument, the informants’ comments on keypal activities written in July, two times of individual interviews and the researcher’s observation report. One major finding emerged from the data is that there were four types of autonomy development. Some implications drawn from the study findings are added for future keypal-based English-learning autonomy development programs.