Abstract: This paper discusses how design-based research (DBR) has been used to investigate the development of OLC4TPD (Online Learning Community for Teacher Professional Development), an online learning community developed in 2009 to support ongoing teacher professional development in Indonesia. Motivated by the sense of urgency to improve teachers’ professional competencies to teach the 21st century generation and to address the challenges of the existing teacher professional development in the country, a technology-based concept of ongoing TPD framework was introduced with reference to existing literatures and trends. A full cycle of DBR procedures was conducted to intervene in the existing practice, which resulted in the formation of the online community of practice of educators. This online community has reached out to teachers from different places in the country and engaged them in the process of knowledge building and sharing through online and face-to-face interaction. This paper describes four phases of the DBR process of OLC4TPD implementation in Indonesia.