The study aims to explore the major concerns on textbook design shown by the review committee on elementary school social studies textbooks. The research design included content analysis and an interview approach. A total of 12 textbooks from 3 publishers were involved in this study, each textbook with one set of Textbook Review Comments. Quantitative content analysis was employed to examine the committee's concerns based on the 12 sets of Textbook Review Comments. A semi-structured interview was conducted with five committee members to explore their concerns on textbook design. The major findings of the content analysis and interview were coherent: the most important concerns on textbook design were text and graphs/charts; the least important concern was the layout. The key underlying principles expressed in the reviews were the accuracy of the materials, the fluency of the text design, highordered thinking, and multiple and balanced perspectives.