One of the most important elements in the preparation and compilation of educational books in general and English language teaching (ELT) textbooks in particular, is Visual element. In recent decades, various instructional theories and models have dealt with such elements in terms of type and role. Due to their importance, they are categorized into two main groups: (a) pictures (image, drawing, painting, animation), and (b) graphic organizers. In this paper, first they are presented through several perspectives. Then, considering the importance of English for specific purposes (ESP) textbooks published by SAMT in the academic community of Iran, through a descriptive and analytic approach, the authors tried to analyze this component quantitatively and qualitatively and in proportion to its role and function in three periods of ESP textbooks development. The results indicate that this component has been specially developed in the new generation of specialized books and has been largely overlooked in the second generation and especially in the first generation. In the third generation, we also see strong points and, of course, weaknesses in terms of the amount and type of visual elements, which are different based on various disciplines of textbooks. Therefore, while investigating and analyzing these cases, some suggestions have been made to strengthen this component.