The objective of this study is to practice introspective writing using letters based on the characteristics of reflective writing. In the meantime, there have been several researches focusing on reflection in the writing process or reflection through sharing with others. However, this approaches were not suitable for the nature or purpose of introvertive writing. Introspective writing is an activity that has its own personality in content and form. For introspective writing, the production of writing is personal and the process of consumption is introvertive. In this regard, the study presented six premises for introspective writing. Based on these principles, I proposed < the Monthly Letter to Myself >. In addition, after conducting < the Monthly Letter to Myself > activity, the questionnaire was conducted to analyze students' perceptions of letters. In conclusion, the students conducted introspective activities through their monthly letter and hoped to continue their introspective writing.