The aim of this paper is to investigate characteristics of professionaldevelopment within the online teacher community. For this, a researcher analyzed‘Band’, synchronic SNS tool and ‘Online cafe’, asynchronic online cafe usinginternet ethnography as a research method. ‘Band’ and ‘Online cafe’ were utilizedas a means for professional development of elementary school teachers whoparticipated in the training course of 40 professionals about curriculums. Aresearcher collected data through participant observations, interviews, andself-reflection diaries and then analyzed the information gathered. Mostimportantly, a researcher combined online participant observations and offlineinterviews to solve ‘internet paradoxes’, which is the problem of internetethnography. Data was analyzed using 3steps; transcription, coding, and themefinding. And then, the researcher proposed characteristics of online teachercommunity based on 7 key words; sharing, teacher training, research, reflection,collaboration, practice, and support. The characteristics of the online communityconsists of 4 results, sharing activity integrated synchronic and asynchronicinteractions, online learning community directed practices, collective intelligencebased on network collaborations, and the reflection of the teachers community topromote professionalism.