Conceptual understanding, which permits one to transfer an explanation of a phenomenon with different ways is clearly a goal in science learning. One way to achieve conceptual understanding is using simulation. The purpose of this review is to analyze the effectiveness the impact of the use simulation on conceptual understanding in science learning. Based on the literature review, significant aspects of how such simulation influence on conceptual understanding is identified. The finding indicated that simulations work to improve understanding the concept of science, not only students’ understanding but also pre-service teachers’ understanding.