Among the various forms of bilingual education in the United States, dual language immersion education has grown rapidly during the past decades (Lindholm-Leary, 2001; Wilson, 2011). Particularly, while the implementation of Mandarin Chinese immersion programs attracted educators and stakeholders' interest, limited attention was paid to research studies on the Mandarin immersion program teachers' lived experiences and teachers' beliefs regarding program curriculum and classroom instruction. This study aims to understand the factors that influenced Mandarin immersion program teachers' professional experiences by listening to teachers' voices and stories shared via semi-structured interviews. The participants in this study include twenty-one Mandarin immersion program teachers who are currently teaching in the U.S. public elementary schools. The findings of this study address global themes on challenges and opportunities teachers encounter at work, collaboration within the school community, as well as language use and language policy in their Mandarin immersion programs. More specifically, this study sheds light on teachers' experiences and beliefs regarding selecting instructional materials and resources, seeking collaborations with colleagues, parent involvement to promote students' learning, power dynamics and inequities in the workplace, and the conflict between the Mandarin-only policy and language use in their classroom. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]