This chapter presents the two fields which provide theoretical foundations for the analytical framework of coherence construction in multimodal texts in this book and the genre-based analysis of the English learning advertisements：coherence and multimodality.Section 2.1 reviews the area of coherence studies in purely linguistic texts.This review identifies the need for a multi-level theoretical framework for analyzing and discussing coherence construction in all kinds of discourses，and some of its features and principles might be shared by multimodal discourses.Section 2.2 provides an overview of the development in the field of multimodality，including the works of theoretical pursuits and the application of the multimodal approach to specific genres.Special attention is paid to the studies on inter-semiotic relations in multimodal discourses because of their relevance with discourse coherence which is the central theme of this book.Section 2.3 summarizes the reviews in the previous sections，with special emphasis on the possibility of adapting the principles in the coherence construction in purely linguistic texts to the English learning advertisements as a complex multimodal genre.