Many factors affect theteaching of massively open online courses. In this study, to explore the factors that influence theeffectiveteaching of MOOCs, a large number of relevant studies are analyzed. Based on grounded theory, semi-structured interviews were conducted with 30 students and teachers who used MOOCs for onlineteaching. The interview data were subjected to four research processes –open coding, axial coding, selective coding, and saturation testing– to explore the factors influencing MOOCs’effective (...)teaching and the interactions between them. The results demonstrate that:Effective teachers,effective tuition,effective communication, active online learning, social support guarantees, and online course design have important positive effects oneffectiveteaching, while only certain online learning behaviors will seriously affect theteaching effectiveness of MOOC, resulting in negative effects.Effective communication is essential foreffectiveteaching in MOOCs;effective teachers are the leading factor, thus teachers should take the initiative to study and understand the students to understand their various learning needs and difficulties. Reasonable andeffective classroomteaching design is key to improving MOOCs’teaching efficiency. E-learning is respected, cared for, and valued by society, including cognition, emotion, and learning platform support from family, school, teachers, and classmates, and has an important impact on students’ motivation and the effects of online learning. The results of this study further clarify factors influencingeffectiveteaching of MOOCs, thus helping to enrich and supplement the theory ofeffectiveteaching and evaluation and providing theoretical guidance for teachers to effectively implement MOOCteaching. (shrink)