This article examines the process of students' conceptual change involving thermal expansion as a result of employing the Dual Situated Learning Model (DSLM) (She, 2001, 2002) as a classroom instructional approach. The dual situated learning events of this model are designed according to the students' ontological viewpoint of the science concepts as well as the nature of these concepts. Moreover, these events serve two functions in creating dissonance with the pre-existing knowledge and providing new schema for constructing a more scientific view of the concept. DSLM has been shown to promote students' conceptual change using one-to-one instructional procedure (She, 2002). This study further demonstrates that DSLM holds great potential to facilitate the conceptual change process involving thermal expansion through classroom instruction, even the difficult concept or higher hierarchical level one.