Readability is one of the important factors for students to consider when choosing a text to read. Based on a self-built corpus of Junior High School textbooks in China, this paper mainly investigates the differences in readability between reading texts in junior high school English textbooks. From vocabulary, sentence, and comprehensive indicators, this study makes quantitative statistics on the factors that affect the readability of English textbook texts to understand the readability of different textbook texts and to explore whether there are differences in the readability of eight textbooks. Finally, the results show significant differences in the readability of the eight editions of English readers. The average word length and new words rate are the highest in Popular Science Press, which reach 4.43 words and 8.40%, respectively. Among the average sentence length and the frequency of compound sentences, the Shandong Education Press has the highest, going 11.36 words and 11.03%, and confirmed that the Shandong Education Press has the highest difficulty. The textbook arranger can take the difficulty of the reading text into account once they have determined the readability of the text. They can then arrange or select a textbook appropriate for students, enabling them to comprehend and master the text more effectively.