There are pre-inquiries (pre-class questions) in which students present pre-class learning contents based on their preconceptions and experiences. Although there are many meaningful pre-inquiries that are closely related to the curriculum, teachers often neither understand nor solve the questions properly. Therefore, this study investigated the pre-inquiries of students and conducted a comparative experiment to analyze the effects of the pre-inquiry solving instruction strategy on academic achievement, scientific inquiry ability and scientific attitude. For the study, two classes of elementary 6th graders, which were found to be homogeneous by a pre-test, were examined as an experimental group and a control group, and then pre-inquiries of the students in the experimental group were collected through questionnaires. Among the collected pre-inquiries, only those related to the learning contents were addressed at the beginning of each class, through group activities. A variety of answers were presented by the students and generalized into the final learning goal. According to the results of t-tests, the experimental group showed significantly higher science academic achievement than the control group (p<.05). In science inquiry ability, the experimental group was better at inferencing, predicting, hypothesis setting, and generalizing than the control group (p<.05). Scientific attitude was also significantly higher in the experimental group than in the control group (p<.01). These results, confirm that students' scientific ability improveds when their pre-inquiries are answered during the class.