The aims of the paper is to examine textuality of science textbooks based on the role of textbooks in science education. Textbooks have been written according to guidelines for effective learning. We consider the importance of writers` intentionality and learners` acceptability in text production and use. We attempt to analyze the textual structure and language used in science textbooks and how they affect the embodiement of writers` intentionality and learners` acceptability. As the first step, we offer general characteristics of the textbook as a text. Secondly, we argue that educational policy and discourse community rules are critical factors in embodying the intentionality into the text structure in science textbooks. Thirdly, we examine the way of embodying acceptability into text structure and language uses, grammatical forms of predicate, style and metaphor in science textbook.