Two quasi-experimental studies (a pilot study and a main study) were carried out to investigate the effects of metaconceptually-enhanced, simulation-based inquiry learning on the 8th grade students' conceptual change in science and their development of science epistemological beliefs. In each of the studies, the students engaged in simulation-based science inquiry learning activities over a period of two weeks, supported by different simulation guides. One guide was enhanced with metaconceptual intervention while the other was not. The findings from both pilot study and main study led to the following conclusions: (a) metaconceptual intervention can enhance simulation-based learning by significantly reducing science misconceptions, but it is not as effective in changing students' mental models consisting of multiple interrelated key concepts; (b) students' beliefs about the speed of learning and the construction of knowledge are strong predictors of their conceptual change and learning outcomes; (c) epistemologically more advanced students do not benefit more from the metaconceptual intervention than those with less mature epistemological beliefs; (d) inquiry learning and metaconceptual intervention have limitations in their promoting of students' development of science epistemological beliefs. Theoretical and practical implications as well as directions for future research are discussed.