This study aims to investigate the written interaction of EFL learners in the blogs. Participants of the study were 25 English majors at Tamkang University, Taiwan. All of the students’ postings and their responsive messages were analyzed to explore the favorite topics which the students share and discuss with others in the blogging context. A questionnaire was delivered to the students at the end of the experiment for the speculation about their perception of blog writing and their attitude toward this blog project. The research findings revealed that a majority of students favored the topics related to self-disclosure and immediate concerns in the blog postings. The preference for certain topics was influenced by the students’ purposes of writing blogs. Moreover, the students frequently used emoticons to express their feelings and sometimes inserted photographs or pictures in their postings. The flexibility of expression themselves in the blogs held a fascination of blog writing for most of the students. Finally, the results of the study showed that blog interaction occurred most frequently in a way of presenting opinions and making suggestions and in the postings written by enthusiastic bloggers. There is no significant relation between the most popular topics and the topics responded the most.