Textbooks considered as one of the most important genres of academic writings would guarantee effective teaching and learning in EFL/ESL courses. Since textbooks are gaining more and more importance, the knowledge of their rhetorical organization that provides learners and teachers with efficient use of their content seems necessary. This article describes the rhetorical organization of the textbook genre based on Parodi’s three-tiered framework consisting of macro-move, move, and steps, which provides a detailed description of a textbook as an extended and lengthy genre. This study aims to rhetorically investigate four ESP textbooks written for undergraduate university programs for accounting students that were developed and published by Payam-e Nour University (PNU), as one of the largest universities in Iran. In order to fulfill the goals, the article aims to investigate the changes made over time in terms of move analysis between two series, each include introductory and advanced ESP textbooks, as well as explicate moves, steps, and their communicative purposes with their accompanying examples. The results aiming at enhancing learners’ and teachers’ perspective toward this genre provide a vivid picture of different rhetorical parts associated with various communicative purposes.
