This study investigated how the acceptance and use of self-regulatory strategies in online learning affected Hong Kong secondary school students' participation in online learning. A self-reported questionnaire was distributed to 1381 students from six secondary schools. Findings of the descriptive analysis indicated that students did not frequently use most types of online self-regulatory strategies. Although they agreed that the online learning methods were easy to use and facilitated learning, they did not actively participate in online learning activities and showed a low tendency to continuation. Further, structural equation modeling indicated that the effect of strategy use on actual participation was stronger than that of user acceptance. The former had a significant indirect effect on actual participation through the strong effect it had on user acceptance. Consequently, suggestions have been made for improving the instructional design of online learning and increasing students' willingness and readiness to participate in online learning.