This study aims to discuss the knowledge sharing of administrators in elementary schools with semi-structure interview to collect data, participant observation, and documentary research. It intends to find out the motivating factor in administrators' knowledge sharing, the specific action to practice knowledge sharing, and the effectiveness of knowledge sharing. The research conclusions are summarized as below. 1. Motivating factors in knowledge sharing: It originates from the mutual trust of administration teams, the regulation of formal meetings in the organization, the identification with and the achievement of administration action, and the personality trait of being glad to learn and share. 2. Specific action of administrators practicing knowledge sharing: It conforms to the viewpoints of learning, communication, and market and is able to apply formal meetings, community network, and media. 3. Knowledge sharing could induce self-growth, enhance administration efficacy, and activate organizational climate. According to the research result, suggestions are proposed for the reference of education administration institutions, elementary schools, and future research.