This study used content analysis to examine the most studied conceptual change factors that influence students' science learning processes and their learning outcomes. The reviewed research included empirical studies published since Posner et al. proposed their conceptual change model 30 years ago (from 1982 to 2011). One hundred sixteen SSCI journal and full text articles were sampled from the Education Resources Information Center database. "Conceptual change" in the title of the articles was used for screening the articles. The results showed that learning outcomes chiefly examined students' conceptual change and their science achievement. The most studied factors influencing conceptual change were associated with instruction and personal reasoning ability. As for instruction, multiple instructional methods were usually integrated in the research, and "conceptual conflict" and "cooperative learning" were found to be gaining the most attention. In addition, certain instructional methods were more frequently linked to specific science subjects. Educators require knowledge of conceptual change theories and strategies. Such information should be more readily available in order to develop teachers' pedagogical content knowledge and help them put it effectively into practice.