朱子義理在中國哲學史上之定位，是當今學術界爭訟問題之一。本文將嘗試從本性論立場，以探討朱子本性思想是否與傳統本性論一致。而在探討此問題前，必先瞭解朱子所謂「性」或「性理」與中國傳統「本性」之意涵是否等值，故本論文將先探討朱子「性」或「性理」之意涵？它屬何類型之「理」？其內涵為何？本文首列朱子「性」之五義，五義中唯「性理」一類屬本文探討範疇；接著分析歸納朱子文獻中得出「四類六種」之「理」，其中「本性論之理」乃為本文所要探討之「理」。最後，說明朱子規定「性理」之內容為「仁義禮智」，世間各種德目皆綜攝於此四理下，而四理中「仁」又為眾理之長，由此形成一組織嚴密，階次分明之「性理」架構圖。朱子如此之「性理」內涵，宜與傳統哲人本性論思想有距離；故知就本性論立場言，朱子義理或非正統哲學之思想。

Position of metaphysics of Chu Hsi in Chinese philosophy history has been one of the disputes in modern academia. From perspective of Theory of Human Nature, this study tries to find if Nature of Chu Hsi is consistent with traditional Theory of Human Nature. Before the exploration on this issue, is ＂Nature＂ or ＂Nature of Reason＂ of Chu Hsi equal to traditional Chinese ＂Nature＂ ? This study first probes into the meaning of ＂Nature＂ or ＂Nature of Reason＂ of Chu Hsi? What kind of ＂Reason＂ is it? What is the content? Five reasons of ＂Nature＂ of Chu Hsi are first introduced. Among five reasons, only ＂Nature of Reason＂ is the scope of this study. This paper analyzes and generalizes literatures on Chu Hsi and obtains ＂four categories and six types＂. ＂Reason of Theory of Human Nature＂ is the focus of this study. Finally, this study suggests that ＂Nature of Reason＂ of Chu Hsi refers to ＂benevolence, reason, manner and intelligence＂. Among four reasons, ＂benevolence＂ is the first. The virtues in the world are included in these four reasons. Thus, it forms the framework of ＂Nature of Reason＂ with precise organization and specific levels. Content of ＂Nature of Reason＂ of Chu Hsi is different from Theory of Human Nature of traditional philosophers. Thus, from perspective of Theory of Human Nature, Metaphysics of Chu Hsi might not be the thought of classic philosophy.