The present study has aimed to predict research spirit in female students based on transformational teaching and the intermediary role of positive youth development and classroom emotion.  For this purpose, 247 female tenth- and eleventh-grade students from private schools in District 4 in the city of Tehran were selected by means of stratified random sampling and asked to complete questionnaires devised by Beauchamp et al. (2010) for transformational teaching, Shirzad et al. for research spirit (2016), Geldhof et al. (2014) for positive youth development and Titsworth et al. (2010) for classroom emotion. Data analysis, using PLS software, pointed out transformational teaching to exert a direct, positive effect on students' research spirit. Moreover, the indirect, positive effect of transformational teaching is only significant, among the components of positive youth development, in the component of care when it comes to research spirit. As of the classroom emotion components, only the emotional capacity component proved to have an intermediary role in the correlation between transformational teaching and research spirit. The indirect effect of transformational teaching upon research spirit is also positive by means of the arbitration of this component. The results obtained from the research indicate the significance of learners' perceptions of the educational environment and classroom emotion in enhancing research spirit.