In recent years, there has been an increasing interest among language educators in implementing and researching collaborative learning in wiki-based learning environments. However, little empirical evidence has been reported about the role of EFL learners' online self-regulating capacity in their collaborative learning. This study used wiki-based literature circles as an instructional method to engage EFL learners in collaborative learning. Using a mixed research method, this study examined the under-researched relationship between learners' online self-regulation and their attitude toward learning through wiki-based literature circles activities. Quantitative data were collected from two surveys, the online self-regulated English learning (OSEL) and the attitude toward wiki-based literature circles (AWLC), among 228 university students in China. Qualitative data were collected from a follow-up interview of 13 participants to explore further the interplay between the students' online self-regulation and their attitude. The results indicated that students hold positive attitude toward learning through wiki-based literature circles in terms of perceived usefulness, self-efficacy, affection, and behavior. The findings partially confirmed the positive correlations between students' self-regulated learning strategies and their attitudes. More interestingly, stepwise regression analysis revealed that students' goal setting acted as a significant predicator of their perceived usefulness of and self-efficacy in completing wiki-based literature circles activities. Self-evaluation was found to be the variable to predict the learners' affection for and behavior in doing this task. This study highlighted the positive role of students' goal setting and self-evaluation for explaining their attitude toward wiki-based collaborative learning. Pedagogical implications and future work are also addressed.