本文旨在探討「研究莊子本性論」之方法；歷來學者對莊子本性論之探究方法，主要有兩路：一是以外雜篇之「性」為莊子論性之內容，此以唐君毅先生為代表；一是以內篇之「德」為莊子論性之內容，此以徐復觀先生為代表；經本文考查結果，發現此兩路都有論證上瑕疵。 於是本文提出「前理論期研究法」與「範疇學研究法」，前者是指在本性論尚未發達前的哲人，他們對本性論之看法雖未以「性」等概念表達，但會將對本性之認定體會等，自然流露於其言談著作中，透過紬繹此等資料，便能條理出該哲人對本性之看法。後者是利用生命實踐哲學四向度七範疇之有機關連性，透過本性論以外諸範疇之內涵論定，便可間接推論出該哲人對本性之看法。 本文以為透過以上兩法之運用，似能對研究莊子本性論有所助益，也較能探究出莊子本性論之真實意涵。

The purpose of this paper is to study research method of "Chuang Tzu's Theory of Human Nature." In the past, researchers had two ways to examine Chuang Tzu's Theory of Human Nature: One is "nature" in miscellaneous chapter, the content of Chuang Tzu's theory of human nature by Mr. Tang Chun-yi, a representative scholar in this field; the other one is "virtue" in internal chapter by Mr. Hsu Fu-kuan, a representative scholar in this field. After textual research, both methods are proven to be flawed. This paper proposes "research method of pre-theory period" and "categorism theory research method;" the former focuses on scholars before the time Theory of Human Nature got its popularity. Their perspectives and cognition of human nature are expressed naturally in their speaking and writings; through data interpretation, scholars' opinion of human nature may be organized. As to the latter research method, inter-correlated four-dimensional seven-scope life practice philosophy is used to indirectly infer those scholars' opinion of human nature through content discussion beyond the scope of Theory of Human Nature. By using the two research methods, this paper seems beneficial to the study of Chuang Tzu's Theory of Human Nature, which may help examining true content of the theory.