This study discuss the leveling of reading texts in the English textbook entitled “Bahasa Inggris” for X grade of senior high school 2013 curriculum, published by “Kementerian Pendidikan dan Kebudayaan” in the year of 2016. This study is intended to find the leveling of reading texts in the English textbook entitled “Bahasa Inggris” for X grade of senior high school 2013 curriculum, published by “Kementerian Pendidikan dan Kebudayaan” in the year of 2016 based on the Flesch Readability Formula (Reading Ease Formula) theory by Rudolf Flesch. The method of this study used descriptive qualitative approach. The data analysis are from the reading texts in the English textbook “Bahasa Inggris” for X grade of senior high school 2013 curriculum, published by “Kementerian Pendidikan dan Kebudayaan” in the year of 2016. The data analyzed by counting the number and average of sentences, words and syllables of each text used Flesch Readability Formula (Reading Ease Formula). Finally, the researcher interpreted based on the result. The result showed that from 10 texts 1 narrative text is in the very easy level, 2 narrative texts are in the easy level, 2 (1 descriptive and 1 recount) texts are in the fairly easy, 3 (2 descriptive and 1 recount) texts are in the fairly difficult, 1 recount text is in the difficult level, and 1 recount text is in the very difficult. Since the texts in fairly difficult level are higher than other texts, it means that according to the theory of Flesch Reading Ease the texts are in the appropriate level for tenth grade students.