The concept of "professional learning community" (PLC) has been suggested as a tool to improve teachers' professional competency and students' learning outcomes since the mid-1990s. In such a community, teachers can share their individual practices with the aim of searching for "good practice" based on the outcome of collective inquiry. Such a learning process will result in a reculturing of the school community by reshaping the existing values and cultures and resolving problems such as teacher isolation and individualism. China already has a long tradition of teachers working and learning collaboratively, so investigating collaborative efforts in this context may provide a view of how to contextualize professional development of teachers in schools. This study attempts to access teachers' lenses in order to explore their views on the effects of subject-based professional learning activities. This also helps to explain how teachers work and openly share their practices aiming at improving their professional competency and student learning outcomes within their communities. Also, factors influencing the sustainability of a professional learning community will be discussed. (Contains 1 table and 2 figures.)