This study was based on the framework of the conflict map to facilitate student conceptual learning about causes of the seasons. Instruction guided by the conflict map emphasizes not only the use of discrepant events, but also the resolution of conflict between students' alternative conceptions and scientific conceptions, using critical events or explanations and relevant perceptions and conceptions that explicate the scientific conceptions. Two ninth grade science classes in Taiwan participated in this quasi-experimental study in which one class was assigned to a traditional teaching group and the other class was assigned to a conflict map instruction treatment. Students' ideas were gathered through three interviews: the first was conducted 1 week after the instruction; the second 2 months afterward; and the third at 8 months after the treatment. Through an analysis of students' interview responses, it was revealed that many students, even after instruction, had a common alternative conception that seasons were determined by the earth's distance to the sun. However, the instruction guided by the framework of the conflict map was shown to be a potential way of changing the alternative conception and acquiring scientific understandings, especially in light of long-term observations. A detailed analysis of students' ideas across the interviews also strongly suggests that researchers as well as practicing teachers need to pay particular attention to those students who can simply recall the scientific fact without deep thinking, as these students may learn science through rote memorization and soon regress to alternative conceptions after science instruction.