The purpose of the research is to investigate how teacher leadership applies to teacher professional learning communities. The subject of the research is the teacher professional learning communities in Chun-Xiu (a pseudonym) Elementary School. Case study was adopted in this research. Twelve teachers were interviewed at this school. The findings are as follows: 1.Teachers' professional growth is advanced by sharing information and teaching experiences in the clubs. 2. Teachers are willing to share responsibilities and cooperate to develop teaching materials in a positive way. 3. The chairmen in the communities are entitled fully by the administrators. 4. Not only are the teachers' teaching skills enhanced, but also the students' motivation is increased to a high degree. 5. The administrators are very supportive and provide different kinds of services.