Learning occurs through various processes. Among these processes, conceptual change has a pivotal part. This article discusses briefly conceptual change in physics. Anchoring on Kuhn's original explanation of theory change in science, this article elaborates especially on the influence of children's science concepts in general, and pre-conceptions and misconceptions in learning process in particular on conceptual change in the science classrooms. Key teaching strategies that build on pupils existing ideas as well as cognitive conflict approaches, to facilitate conceptual change process in school physics are summarized.