Studying ancient Chinese logic under the framework of modern logic can be traced back to the 1960s. Over past decades or so, this approach has been widely advocated and employed by many researchers. The reason for proposing this new approach, on one hand, is a result of the development of ancient Chinese logic studies. Scholars have realized that ancient Chinese logic is incomprehensible under the methodology of western traditional logic. On the other hand, ancient Chinese logic studies were inspired a lot by the studies of history of western logic. The general procedure of studying ancient Chinese logic under this approach is as follows: first, formalizing the arguments in the text, second, representing the complete process of arguments using the modern logic rules. Different ways of formalizing the arguments in the "Discourse on White-Horse" showing in the current paper demonstrates this approach depends on researchers' understanding of the texts. This approach serves as a way to spread modern logic and will contribute to the development of modern logic. Furthermore, whether it is helpful in the understanding of the ancient Chinese text as well as its arguments was discussed in the present paper.