The purpose of this study is to analyze phonics in English textbooks for Grades 3–6 developed under the 2015 Revised National Curriculum. Two textbooks were analyzed in terms of content and learning activities of phonics to determine the implications for the formation of phonics in future textbooks. Based on the results, the following conclusions were obtained. First, since the quantitative deviation of phonics between textbooks is an issue that has already been identified in previous research, it is imperative for future curriculum to provide guidance to reduce this variance in phonics learning provision. Second, guidelines on the order of presentation of phonics rules should be provided to enhance the efficiency of phonics learning, and accordingly, further studies dealing with Korean elementary school English learners should be investigated. Third, in order to make it easier to use phonics vocabulary in the textbooks that can easily infer the relationship between sounds and letters, it is necessary to review and supplement the vocabulary list presented in the current curriculum. Fourth, it would be appropriate to present phonics rules that are more difficult in terms of its hierarchy in Grades 5 and 6 to enhance continuity and effectiveness, while reducing the burden of phonics learning in Grades 3 and 4. Finally, the development of differentiated phonics activities should be conducted taking into account the developmental characteristics of each grade. It is also imperative to try various compositions of phonics activities to provide proper learning time.