Abstract This thesis includes six chapters in total. Besides the first chapter presenting the purpose and process of writing and the sixth chapter concluding arguments, the structure and approaches of this thesis are as follows: This thesis consists of two parts. The first part, including the second and the third chapter primarily, introduces the concepts of legal transaction" and the existing doctrines concerning the basis of the effect of legal transaction. The second part, including the forth and the fifth chapter, explores in depth the subject matter: the theory of flexible system and a flexible system approach to the basis of the effect of legal transaction. The second chapter aims to set the scene for this thesis writing. This chapter briefly describes the legal transaction terminology, the concept of legal transaction and its transmission. The third chapter explores the existing theories concerning the basis of the effect of legal transaction. The study of this chapter concludes that the effect of legal transaction cannot be explained through a single factor. The fourth chapter introduces the system thinking and the flexible system theory. In the fifth chapter, we will verify the regulations regarding the effect of legal transaction in the Civil Code of Macao comply with the theory of flexible system. Eventually it reveals that the regulations regarding the effect of legal transaction in the Civil Code of Macao conform to the theory of flexible system.

摘要 本文將共有六章。 除用於說明論文的寫作目的與過程等事宜的第一章以及歸納論點的第六章外，論文的结構和思考路如下: 第二章和第三章為上篇，第四章和第五章為下篇。上篇主要介绍法律行為的概念與現有的關於法律行為效力依據的理論現狀，下篇将深入主题，探討動態體系理論以及法律行為效力依據的動態體系。 第二章旨在為論文的寫作作場景設定，在本章中將簡述法律行為之術語、法律行為的概念以及傳播。 第三章將對現有的法律行為效力依據的各種理論进行探討。這一章的小結中將得出的结論是:透過單一要素無法解釋法律行為效力。 第四章將會介绍可以協調多項要素的體系思維以及動態體系理論。 在第五章中，本文將驗證《澳門民法典》關於法律行為效力的規定是否符合動態體系理論。最终可以發現《澳門民法典》關於法律行為效力的規定符合動態體系理論。