Legislation is the first official، original and the most important and widespread source of law. In this section، the definition، importance، the way of enactment and the stages of composition of legislation are revealed in further detail. After that، other law texts related to and similar to legislation are elaborated; these include Constitution and legal systems and their relationship with legislation. Both the role of the judiciary in controlling the constitutionality and legality of legislation، and interpretation of and abolish legislation، are addressed further. In this section، and as a result، the legal study includes the following demands: Demand One: The Definition and Importance of Legislation Demand Two: The Characteristics of Legislation Demand Three: The Types of Legislation Demand Four: Judicial Oversight of the Validity of Legislation Demand Five: Interpreting Legislation Demand Six: Abolish Legislation This version is archived in the Arab International University(AIU) repository for open access and dissemination purposes. The content of this paper has not been modified from the original publication. for more information, please visit the official repository of Arab International University (AIU) https://www.aiu.edu.sy