Many researchers have indicated that the prior knowledge has great effects on students' performance in learning mathematics. The low prior knowledge (LPK) students were expected to have lower learning performance and achievement than those of high prior knowledge (HPK) students. To help the low prior knowledge students, researchers suggested that to provide a self-regulated learning (SRL) support may be effective and helpful. However, the prior knowledge might also affect students' self-regulated learning. Thus, the relationship among SRL, prior knowledge, and learning performance remain unclear. To deal with this issue, this study not only investigates whether an enhanced SRL is helpful for students to improve learning performance but also explored how HPK and LPK students behaved differently when interacting with the SRL environment. The results suggested the SRL environment offers opportunities to remove the gap caused by prior knowledge in long-Term. Accordingly, further finding, and implications are discussed.