It is now possible to create flexible learning environments without time and distance barriers on the internet. However, research has shown that learners typically experience isolation and alienation in online learning environments. These negative experiences can be reduced by enhancing social presence. In order to better facilitate the perceived social presence in online classrooms, this study presents a framework developed from the social cognitive theory for investigating social presence and its relationships with relevant factors. An instrument with sufficient reliability and validity was developed to measure these factors. A formal questionnaire-based survey was carried out among learners with previous learning experiences in online learning environments. A total of 522 valid samples were collected from three schools and analyzed using structural equation modeling to examine the proposed framework and hypotheses. The results show that user interface and social cues have significant effects on social presence. User interface also has significant effects on social cues. Moreover, this study evidenced that social presence has significant effects on learning interaction which in turn has significant effects on learning performance. Finally, implications of the findings were discussed for further research directions and practical applications.