This paper provides ethnographic accounts of Sasang medicine in standardized settings. The ethnography explores how Sasang medicine, which is regarded as a unique traditional medicine in Korea, is taught in a school of Korean medicine (KM) which provides both classroom and hospital teaching. Although Sasang medicine traditionally has its own medical doctrine and way of practice, it is taught alongside other subjects relating to Korean medicine in the last two years of the 6-year course. Such standardized education in the school has bestowed different forms of learning Sasang medicine. However, this paper argues that there is a paradoxical coexistence of traditional and standardized learning in the setting. For example, although the standardized textbook of Sasang medicine is used during classroom learning, there is still a strong emphasis on understanding the founder’s life, thoughts, and his seminal texts. In the hospital-based learning, although more technological devices and standardized tools - e.g. diagnostic tools or questionnaires - are used in the learning process of Sasang medicine and students are also required to perform doctor-patient role playing as a part of the Objective Structured Clinical Examination (OSCE), there still exists the authority of the classics, which is likely to precede the standardized tools. To demonstrate this paradox in the standardized setting, this paper particularly focuses on how the ‘constitutions (Ch'ejil)’, which are the pivotal concepts of Sasang medicine, are made in the setting. In doing so, this paper aims to show how the concept of ‘constitutions’ is narrated, debated and negotiated.