The purpose of this study was to explore the sources of efficacy beliefs and teaching behavior characteristics related to positive teacher efficacy among elementary school teachers. Twelve teachers from southern Taiwan with high teacher efficacy scores, who were nominated and recommended by colleagues, were invited as interviewees. Constant comparative method was used to analyze collected data. The findings were twofold. First, the sources of efficacy beliefs of participants included mastery experience, the relationship between the teacher and students, role models, social support, and personal qualities. Second, in consideration of individual teaching ability and beliefs, student qualifications and their parents’ responses, adaptive and skillful teaching behaviors that cultivated students’ morality were teaching behavior characteristics reported by the participants. Based on the above results, discussion and implications are provided for using positive teacher efficacy to promote teachers as a human resource and for their professional development as well as for further study on this topic.