UX (User Experience) Design was an interdisciplinary approach in humanities, engineering, science and design. We classified the roles of user experience; requirement analysis which are user research, constraints analysis and direction analysis, concept design, information architecture, physical UI, graphical UI, sound UI, Olfactory UI, prototype, evaluation, launch, localization, and knowledge management/UI DB. User research methods were classified by the relation of designer, user, and product/service. We reviewed three issues of UX design; complexity management, efficiency management, and mapping management.