This dissertation presents a categorization of existing methodologies of upper register development for euphoniumists with evaluation of effectiveness and current use of these methodologies. The purpose of this study is to provide euphonium musicians as well as educators with essential references and guides to applicable methods for developing the upper register more effectively with greater efficacy. The assessments of current methodologies include three steps: categorization, summarization, and evaluation. To support the significance why it could be more beneficial than the methodology alone, the dissertation will include the examination of the aspect of biomechanics and ergonomics, suggestions, and discussion of particular issues of the upper register.