The Council of Graduate Schools received 749,000 graduate applications by international students in Fall 2018. Though the Open Doors (2018) reported international graduate students at the US institutions decreased by 2.1% from last year, the number of students studying at the graduate level remains high. To any graduate students, receiving funding from the institution studied is crucial for their academic study. It is difficult to secure funding for international graduate students than their domestic counterparts. Many international graduate students choose to teach their native languages in US institutions. This dissertation of case studies explores the experience that three East Asian international Graduate Teaching Assistants (GTAs) encountered at a Midwestern teaching and research institution in the US. The study exposed the perceptions, difficulties and challenges, and future career choices that constructed the learning, social and teaching experiences of these three East Asian international GTAs. Data were collected through in-depth individual semi-structured interviews, informal chats, and the analysis of relevant documents. Essential themes were generated on academic identity, social identity and teacher identity of the participants; the challenges in each identity category were discussed, and implications were provided for graduate programs. [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.]