This study examined how English teachers at elementary school developed their expertise through an online teacher learning community, Indi school. To accomplish this aims, the characteristics and preferences of the uploads were analyzed, and the teachers were interviewed about how the online community contributed to their professional development. The findings indicated that Indi School was equipped not only with materials that reflected the characteristics of the subject, but also resources that aided the teachers in adapting their lessons and addressed the teachers’ and students’ needs. Although the teachers differed in how they utilized these materials, the site was useful as a teacher learning community. While the novice teachers with less than one-year teaching experience tried to apply mastery with apprenticeship, teachers with one to three years of teaching experience used the site as an item bank to reflect their lessons. The ones with more than three years of teaching experience viewed the site as a gallery audience to check current trends. The less experienced were more reliant on the materials, whereas the more experienced perceived the stie with low trust as it lacked the function of providing in-depth consultations. Therefore, this study implies the necessity for providing offline consulting services as well as other scholarships that address the different experiences of teachers and support their professional development.