Studies have been conducted on college students’ experiences to learn online from the perspectives of learning motivation, environment, engagement and effectiveness. However, few have examined how the above factors are relate to each other and the nature of online learning for students across cultural regions. This study used the "categorical-content" analysis method of qualitative research through in-depth interviews with 37 college students. Based on this, it explored the online learning experiences of college students in Macao and constructed a theoretical model. When the mode of learning changed, students faced new challenges and underwent a process of adaptation and transformation. The main research findings include: (a) Whether students have continuous intention to learn online mainly depends on whether students can make reflection-in-action plan in self-regulated learning. (b) The technical environment brings students intuitive experiences, while the potential environment brings students stress-free learning and external interference; (c) Based on the attention on technology and emotion, students have different views on the effectiveness of interaction. (d) Due to cultural differences, local students pay more attention to the emotional experiences, while Chinese mainland students have rational understandings of learning effectiveness. In the interweaving experiences of emotion and rationality, the effectiveness of learning is improved. The recommendations for future online instructional design with a view of improving students’ learning experiences are discussed in this paper.