Keng Ting-hsiang was a scholar of Taichou School, being an influence on the academia of the Late-Ming Dynasty. But in the later period, the scholars were ignored to study his teachings. On the contrary, Keng had had the experience of the continuous debates with Li Zhi, who was a celebrated thinker and positioned an iconoclast and anti-traditionalist. Li advocated staunchly "true Confucianism"; therefore, the scholars regarded Keng as a pseudo-Confucian. However, Li criticize severely for Keng on the one part, but still eulogized that Keng was a sage on the other part. The contradictory evaluations about Keng were out of consideration over a long period of time. This study reviews the critiques and encomiums about Keng Ting-Hsiang from Li Zhi and the other scholars in the Late-Ming history. Then we consider that the evaluation about Keng was prejudiced for a long time. Li Zhi's "true Confucianism" was a distinctive Confucianism about life practice, and he believed that frank friends should redress errors mutually. At the same time, the praises from Li were a certification that the personality and scholarship of Keng conformed to Li Zhi's "true Confucianism". Both the spirits of Li and Keng were the practical wisdom. Therefore, Keng Ting-hsiang was not a pseudo-Confucian, and his scholarship should be researched more deeply.