Cheng Tingzuo was a Mid-Qing scholar of the ”Yijing” 易經who endorsed a reading of the text based in moral principles. Cheng reflected on the fact that his contemporaries' views of the Yi were often influenced by the historical interpretations found in the commentarial tradition rather than their own readings of the work. As a result of this reflective process, Cheng advanced an interpretation of the ”Yijing” that diverged from the standard Cheng-Zhu position, and he expressed doubts regarding the received methods of explaining the text. Cheng's Yi learning, which was based on the ”Xicizhuan” 繫辭傳section of the work, can be said to have three characteristics. First, Cheng differed from earlier scholars, who focused on the hexagrams, by emphasizing the trigrams and by using the trigram images (from the upper and lower parts of the hexagrams) to explain the yao lines. Second, Cheng's philosophy of ”yijian” 易簡 stressed the qian and kun trigrams because they represented, respectively, pure yang and pure yin. Third, Cheng did not adopt the concrete material images of the trigrams, but rather utilized the abstract meanings found in their corresponding virtues. Cheng thus not only reassessed the inherited tradition of Yi scholarship, he also called for a return to the actual interpretation of the text itself. His ”Dayi zeyan” 大易擇言reflects his understanding of earlier Yi learning, while his ”Yitong” 易通 resulted from his decision to return to the classics. Both texts are worthy of our attention.