As the only one Open University of Thailand, Sukhothai Thammathirat Open University (STOU) has provided quality education to a significant number of disadvantaged people including people who would like to further their studies to graduate level in order to improve their academic profession. STOU has successfully has provided distance education through mixed media for decades. However, the outbreak of the COVID-19 pandemic caused both unprecedented disruptions and massive changes to education in many aspects. Even though STOU is a distance education university, some adjustment in the system has to be implemented to suit the current situation. In doing so, the full scale of online distance education has been developed. This paper will present the adjusted practices to online system in the areas of teaching and learning, thesis/dissertation supervision, evaluation, and student support by focusing on the graduate level. Some feedback from the leaners and the challenge issues were also included.