The purpose of this study is to investigate self-efficacy of female elementary students who participated in field-based inquiry activities in Kenting, Taiwan. The subjects of this study are 60 elementary school students in 2 rounds. These students participated in a two-day-and-one-night scientific inquiry activity in Kenting. In these 20-hour courses, the ratio of lecture and field-experience is 4:3. The students were tested before and after the activity with the ＂Science Self-Efficacy Scale＂, and t-test was utilized to know if the results were significantly differend. We obtained four factors, and reliability value of each factor was greater than .7. The students were interviewed during and after the activity. The result showed that ＂achievement performance＂ (t=-2.85, p＜.05), ＂emotional arousal＂ (t=-2.30, p＜.05), and ＂vicarious experience＂ (t=-2.41, p＜.05) were all significantly promoted. However, there was no significant difference in ＂verbal persuasion＂ (t=-1.864, p＞.05). Overall, we believe that Kenting Field-based Inquiry courses are able to promote female students' self-efficacy (t=-2.63, p＜.05). Female students responded with a positive attitude toward this course and they were inspired through the competition. Nevertheless, such courses are usually limited by the environments, time and budgets. We suggest that teacher should take the limitations into account on the basis of the uniqueness of field-based activities, and thus develop suitable teaching materials for various field-based scientific courses.