This paper analyzes how Korean 10th graders read historical texts and suggests several teaching strategies for using historical texts in the class. For this study, I selected three historical texts which have been repeatedly used in elementary, middle and high school Korean history textbooks because I intended to anlayze how students read familiar historical texts. Text 1 is the King Sejeong's Preface of Hun Min Jeong Um(1443), in which the King Sejong wrote why he created the Korean written language, Hun Min Jeong Um, Text2 is several Chosen scholars' letter to the King Sejeong. in which the scholars strongly insisted that Hum Min Jeong Um not be used. Text 3 is a short and edited record of Sejeong and the scholars' conversation. I asked twenty two 10th graders in Seoul and the Gyeongi province to read those texts and answer to my questions: why they insisted that Hum Nin Jeong Um should be used or not be used. I recorded and transcribed the students' answers for analysis and comparison. As a result, I have found that Korean 10th graders' previous knowledge and prejudice on the writers strongly influence their interpretation of historical texts and their ways of making inference of the writers(speakers)' intention from the texts. I suggest that when teachers give and ask students to read historical texts, they need to guide students not to infuse any prejudice into the texts.