The current study examines pre-service English teachers’ reflective journals over the 4-week period of teaching practicum in one Korean middle school and one Korean high school. A total of twenty-one Korean college students majoring in English education completed their reflective journal on “class observation” and “impressions and plans for tomorrow” during the period. Their “mentor teachers’ comments and advice” were also included the journals. All the journal writings were constructed as text corpus and then analyzed through the Antconc programme by stages: introduction (1st week), development (2nd & 3rd weeks), and closing (4th week). As for class observation, the middle and the high school pre-service teachers initially considered lesson planning and classroom atmosphere most important, respectively. In the development stage, classroom observation were thought most importantly for the middle school pre-service teachers and lesson planning for the high school pre-service teachers. In the closing stage, both of the middle and the high school pre-service teachers considered classroom atmosphere as the most crucial factor. Concerning the impressions and plans for tomorrow, both of the middle and the high school pre-service teachers reported that figuring out students and their emotions would be important in the introduction and the closing stages. However, in the development stage, the high school pre-service teachers counted lesson planning as the most important factor. As for the mentor teachers’ comments and advice, both middle and high school mentor teachers regarded lesson planning as important in the introduction stage, and they tried to provide encouragement and help to the pre-service teachers at the closing stage. In the development stage, evaluation for teaching rehearsal and lesson planning were most frequently mentioned from the middle and the high school mentor teachers respectively.