This thesis aims at exploring the Trans-National Enterprise (TNE) as a leading business and economic actor at the international taxation level, and the legal (international tax) framework surrounding it. It is spread over eleven chapters within four main parts; the first part addresses the question of what is the TNE, why is it important, and what is the international tax law that governs it. The first chapter addresses the importance of the THE in the modern world (economy) and the tax implication of that role. The second presents the international tax system that governs the TNE, where the OECD Model Convention claims a significant part. The third chapter explores the notion of the THE and the prospects of applying the enterprise entity theory on the taxation of the THE members. Part two addresses the obstacles against applying the enterprise entity approach on the taxation of the TNE; the fourth chapter examines the legal principles that stand in the way of applying the enterprise entity theory, especially legal separation; the fifth chapter presents the OECD MC's position towards the principles of arm's length and legal separation. Part three addressesth e problems causedb y this attachmentt o arm's length and legal separation; chapter six explores the problems of international tax avoidance; chapter seven explorest he role of legal separationin the different tax treatmentb etweent he PE form and the subsidiaryf orm. Chaptere ight addressetsh e problem of entity classification. Part four explores the prospects of an alternative approach to the taxation of the THE from within the OECD MC, by examining the case for aggregation (consolidation) in chapter nine, and the case for a formula-based allocation (based on the profit split method) in chapter ten. Chapter eleven recapitulates the conclusions from the previous chapters reaching to the final conclusions.