Professional Learning Community (PLC) has been a new paradigm for enhancing Teacher Professional Development (TPD) in recent years. Since the implementation of Macao SAR Legislation No. 3/2012, “System Framework for Private School Teaching Staff of Non-tertiary Education”, various stake-holders of education have advocated teacher professional development in response to the community’s increasing expectations of teachers. In order to find an effective way to promote the professional development of a group of in-service primary English teachers, the researcher has conducted a case study to explore how a PLC encourages TPD in Macao. The author chose the Primary English Panel of a private K-12 school as the research sample and implemented a PLC model. The teachers of the PLC engaged in a variety of well-structured professional development activities: 1) regular panel meetings; 2) a tailor-made pedagogical content knowledge course; 3) a school-based training program related to teaching practice; and 4) peer instructional observations. These activities lasted for almost two years. Data were collected from the minutes of panel meetings, completed questionnaires, semi-structured focus group interview, classroom observation reports/assessments, and direct observations within the PLC. After analyzing the data, the author gained some insights related to TPD, students’ learning and panel culture and practice. The findings of this study are: 1) The Learning Community creates a nurturing ecology for Teacher Professional Development; 2) The Learning Community provides convincing evidence for teachers’ improvement; 3) The Learning Community helps develop a learning and collaborative culture for Primary English Panel (PLC); and 4) The Learning Community has positive impact on teachers’ perception of students’ learning. The iv researcher comes to the conclusion that by adopting the PLC model teachers are able to gain professional development and promote students’ learning. Teacher’s efficacy and a feeling of satisfaction from work are also enhanced.