Using the valid Coh-Metrix tool, this study examined whether there were significant differences between the reading sections of internationally published and domestically developed ELT books. To investigate the textual differences between these two different types of books, as many as 60 English excerpts were randomly selected and analyzed based on the five principal components of narrativity, syntactic simplicity, word concreteness, referential cohesion and deep (causal) cohesion. The samples of this study included reading texts of six books in different grade levels. They were divided into Internationally Published Books ( Facts and Figures, Thoughts and Notions, Concepts and Comments ) and Domestically Developed Books ( Vision 1, Vision 2, Vision 3 ). The reading texts were selected and entered into Coh-Metrix Text Easabality Assessor. This tool analyzes the ease or difficulty of texts on five different dimensions. The results of Analysis of Variance (ANOVA) demonstrated that there was a significant difference between internationally published books in terms of Narrativity, Syntactic Simplicity and Referential Cohesion. The book Concept and Comments was less in the structure of lexicon compared with the other two books: Facts and Figures and Thoughts and Notions . The results indicated that Facts and Figures tended to employ more simple syntax than other books, and the two advanced level books tended to use higher deep cohesion. As for the domestically developed books, there was a significant difference between the three books in terms of syntactic simplicity. The results showed that Vision 1 tended to employ more difficult syntax. The conclusion that can be drawn is that the domestically developed books are different from internationally published books in some linguistics features. Keywords: Coh-Metrix; Narrativity, Syntactic Simplicity, Word Concreteness, Referential Cohesion, Deep Cohesion