This study aimed to determine what is the readability level of English textbook "ENGLISH FOR NUSANTARA" for Junior High School Students in Grade VII and what factors that affect student readability.

For the initial data collection for this study, researcher use document analysis of reading texts book entitled “English textbook for Junior high school students in Grade VII "English for Nusantara."

From the data collected by the researcher, it can be concluded that there are five levels of readability in the book "English for Nusantara" which can be grouped into five sections: one text with a readability score of 90-100, six texts with the score of 80-90, then there are eight texts with the score of 70-80 and three texts with a score of 60-70, and lastly, there are two texts with the score of 50-60. The researcher also found several factors that can affect students' readability level after reading the related journal such as vocabulary difficulty, background knowledge, text structure, passage length. The result of this study shows that most of the texts in the English textbook entitled “English textbook for Junior high school students in Grade VII "English for Nusantara” met the factors in writing texts that are appropriate for the intended class.

The author expects that this study will serve as a resource and starting point for other researchers who wish to do a study on the readability of texts, particularly in English textbooks, in addition to using books as teaching resources, teachers can also plan and choose the right reading materials for their students by checking many different types of sources.