The purpose of this study was to explore and describe the experience of Dan-Jeon breathing training and of Qi as a essential substance in forming human body. The sample consists of 7 participants who are Dan-Jeon Breathing training in a Training center, Pusan, Korea. They were asked open-ended questions in order for them to talk about their experiences. With permission of the subjects, the interviews were recorded and transcribed. 1. The purpose of Dan-Jeon Breathing The interview data was organized by themes into 4 categories: hope for health recovery, a concern about Dan-Jeon Breathing, seeking meaning of life, change of lifestyle. 2. The experience of Qi during Dan-Jeon Breathing training The interview data was organized by themes into 3 categories: an autonomic movement of body, spiritual experience, conviction of existence of Qi. 3. The change after Dan-Jeon Breathing training The interview data was organized by themes into 7 categories: physical health promotion, emotional relaxation, promoting brain function, positive attitude about life, love to others, investigation for self, improvement on Qi feeling.