This study explores changes of the tenth-grade students' conceptions about acids and bases by using conceptual change text oriented instruction accompanied with analogies. Since conceptual change is viewed not only as a process of replacement of old concepts but also a process of learning to relate ideas to appropriate contexts, the instruction and conceptual change text were designed to convince the students that some situations which they understand are actually analogous to other situations which they misunderstand. The results of the study showed that students in the experimental group taking conceptual change oriented instruction performed much better than the students in the control group taking traditional instruction. Thus, one could deduce that establishing analogical thinking during the course of instruction together with a conceptual change text could be a powerful tool for generating an understanding of unknown and misunderstood situations as in the case of acids and bases concept. (Contains 1 table.)