The purposes of this study were (1) to investigate the general status of the traditional healers, the knowledge used in giving the treatment of diseases, the conditions of medical treatment and services of the traditional healers, and the acceptance of the treatment methods of the traditional healers in Loei Province, and (2) to study the process of transformation folk medicine s wisdom on herb using for communities s treatment in Loei Province. The qualitative research methods used included in-depth interview, participatory observation, and focus group discussion. The target population of the study included the registered traditional healers who were still giving treatment to patients in 14 districts of Loei Province and the current and previous patients in the community who received treatments from the traditional healers; community leaders; community elders; and, scholars of traditional Thai medicine. The research results are as following.