The purpose of this paper is to investigate whether the Antarctic Treaty System has the level of legitimacy necessary to ensure adequate protection for and conservation of the fragile Antarctic environment. This work will provide considerable new information in the field of legitimacy as it relates to the Antarctic Treaty System (ATS) as to my knowledge it is the first time an in-depth analysis of the subject has been made using materials from within the ATS. To answer this question this thesis will begin with an investigation of the principle of legitimacy within international law. An overview of Antarctic exploration and exploitation, territorial sovereignty and the development of the ATS will follow this. This section will also contain a discussion on the issue of natural resource sovereignty, as it is this issue that is likely to develop as the major source of Antarctic conflict in the future. This introduction to Antarctic politics is intended to give the reader a complete picture of the political situation that currently exists in the region. The final eight chapters will contain the substantive arguments of this paper. They consist of the application of legitimacy theory to varies situations that exist within the ATS in order to establish whether these events have any adverse effects on the overall legitimacy of the ATS and therefore its ability to adequately protect and conserve the Antarctic environment. The majority of the information for these chapters has resulted from in-depth research or the meeting reports of the Antarctic Treaty Party Consultative and Special Consultative Meetings. Chapter Seven looks at the continued criticism that the ATS represents a ‘closed and exclusive club of rich and powerful states. Chapter Eight investigates whether the apparent conflict between Article IX(2) or the Antarctic Treaty conflicts with the ATS's environmental protection role. Chapter Nine looks at the circumstances surrounding the establishment or the permanent secretarial. Chapter Ten investigates whether the inability of the Parties to establish a liability annex to the Madrid Protocol has effected the legitimacy of the Protocol and by association the ATS. Chapter Eleven is an analysis of the effects that China's non-compliance with the provision of the Convention on the Conservation of Antarctic Marine Living Resources has on the legitimacy of the ATS. Chapter Twelve investigates whether the lack of jurisdiction over tourism in the Antarctic region has had any adverse effects on the legitimacy of the ATS. Chapter Thirteen is an overview of the status of recognition of the ATS within the United Nations. At the conclusion of the analysis of international law and the meeting reports of the ATS contained in this thesis it became clear that despite the current problems that the ATS is experiencing the organisation does have the level of legitimacy necessary to protect the Antarctic environment. The Parties must be aware however that this legitimacy may not continue if they do not address these problem areas in a timely manner.