The purpose of this study was to analyze the effects of experience-based adventure education on self-efficacy of high-risk families' adolescents. The participants of the study were eighth-graders of a junior high school in New Taipei City who joined the programs of adventure education. In-depth interviews were held to develop texts and thematic analysis was adopted for analyzing the texts. There were six essential themes about the self-efficacy of high-risk families' adolescents in rappelling courses of adventure education: confidence building, cooperative learning, problem-solving, self-regulatory, self-regulated learning, and social efficacy. Base on the findings, the researchers presented suggestions for the adventure educators, youth workers and researchers.