While a pandemic is currently sweeping the world, technology becomes a necessity in almost the entire aspects of life, particularly in learning activities. One of conventional learning-based platforms that adopt online system is Moodle Learning Management System. This study explored the argumentation skills of prospective teachers based on commognitive approach using the LMS. This qualitative research used online-based semi-structured questionnaire and interview during a discussion group via LMS platform. The subjects of this study were 38 prospective teachers. The research instrument was a questionnaire with eight items. It was initially assessed with Cronbach’s alpha test in which the value indicated the questionnaire was reliable (0.852). The findings of this study indicate the argumentation skills of prospective teachers correlate with the commognitive framework, including claim with endorsed narratives; data with visual mediators; warrant with routine, word use, and endorsed narratives; and backing with endorsed narratives.