In general, people are mistaken that Dong Zhong-Shu categorizes human nature into three classes, and that Dong’s theory on humanity is against pre-Chin Confucianism principles that everyone can strives toward goodness and to become a Sage by themselves. This article clarifies that the three-category human nature theory is a misunderstanding of Dong’s philosophy of Heaven, in which human nature consists of both Yin and Yan, goodness and badness. In sum, Dong does not categorizes human nature into three classes and his theory on human nature is in line with pre-Chin Confucianism. This thesis starts from Dong’s review on the theory of humanity of pre-Chin Confucianism, from where Dong develops his own.