Past studies have found mixed results of the impact of immersive virtual reality (IVR) environments on students' learning. In this study, we examined the effect of using concept maps, a kind of advance organizer, on students' learning of science via IVR. In this exploratory and immersive learning environment, we also explored the roles played by learners' epistemic curiosity and other affective factors. Seventy-four sixth-grade students participated in this research and were randomly assigned to the advance organizer group (AO; experimental group) and the non-advance organizer group (NAO; control group). Data collection included survey questionnaires and a science test for assessing students' understanding of plants. We examined the structural relationships among students’ curiosity and affective factors (including presence, control and active learning, positive emotional engagement, and negative emotional engagement), and compared the learning outcomes of the experimental and control groups. We used analysis of covariance (ANCOVA) and partial least squares-structural equation modeling (PLS-SEM) for the data analysis. The results showed that students in the AO group had significantly higher scores for science concepts than those in the NAO group. In both groups, the interest-type curiosity and control and active learning positively predicted emotional engagement. Moreover, in the AO group, positive emotional engagement positively predicted the scientific knowledge of plant concepts. Implications for future research and instructional design are suggested in the study. • PLS-SEM was used to explore the roles of curiosity and affective factors. • Students in the advance organizer group had higher scores in science concepts. • The interest-type curiosity positively predicted emotional engagement. • Curiosity interacting with advance organizers made different learning effects.