Due to the recent impact of COVID-19, the form of conventions has changed rapidly to non-contact form. To adapt to trend changes, various attempts are underway in industries. Particularly, online convention has become the most common and universal form of non-face-to-face convention. The purpose of this study was to explore key factors of online convention service quality using a qualitative study method. Participants in the in-depth interview were 10 MICE industry workers who have experience in planning or operating online conventions from September 2020 to January 2021. Interviews were analyzed through the Colaizzi's phenomenological qualitative research method. A total of 71 formulated meanings were extracted based on meaningful answers from interviewees, of which 23 themes, 11 theme clusters and five categories were derived. Five categories were divided into 'quality of presenters and contents', 'quality of online convention platform', 'quality of digital environment', 'quality of service' and 'quality of marketing'. While some of the derived themes were similar to previous studies about service quality factors, this study verified the importance of the quality of speakers and contents, online platform, and digital environment quality that can replace face-to-face events.