本論文主要的宗旨在於陳述天主教社會理論中的社會正義概念的發展，說明此一概念是在何種哲學人類學及世界觀的基礎上發展出來的，並且如此才能指出天主教社會理論的正義概念與上述其他的社會正義概念的區別及其原因。為了達到以上的目的，本論文以概念歷史發展分析為方法，進行概念歷史發展的追溯，分析概念發展與社會結構發展之間的關係。套一句馬克思的術語，就是社會下層建築（Basis）與上層建築（Überbau）之間的關係（貳節）；論述多瑪斯在此概念發展的地位，以及解決理論問題的方案（參節）；介紹塔帕樂理的社會正義概念及其意涵（肆節）；論述庇護十一世之《四十週年》通諭要義及其社會倫理的理論結構（伍節）；最後說明天主教的社會正義觀與俗世的社會正義觀之異同（陸節）。

This paper is mainly focus on stating the development of Justum Sociale concept in the social theory of Catholic Church. And try to clarify on what kind of Philosophical anthropology and world view basis can this concept develop. And only on this perspective we can point out the differences and the reasons between the justice concept in the social theory of Catholic Church and other justice concepts among various theories. In order to achieve our goals, this paper uses the analysis of the historical development of the concept as its method to retrospect the historical development of the concept, and analyze the relations between the concept and the social structure’s developing. As Marx would said, it’s the relations between Basis and the Überbau of the society (part two); In part three, I will expound St. Thomas’ standing in the development of the concept, and the solution about its theoretical problem; In part four, I will introduce Luigi Taparelli’s Justum Sociale concept and its meanings; In part five, I discuss the essence of Pius XI’s Quadragesimo Anno and its theoretical structure of the social ethics; Finally in part six, I will clarify the similarities and differences about the concept of social justice between Catholic Church and the secular perspectives.