Readers' theatre (RT) contests provide a platform for learners to demonstrate the results of their education and to promote language learning. At the elementary school level, young learners often receive intense training before attending a RT contest. However, the contest participants' motivation changes during the training and the affecting factors are often neglected. This study investigates the factors that influence young learners' motivations in RT contest training. Four contestants of an RT contest were selected based on their contest attending experience and ability to express themselves. Data were collected and analyzed through interviews, reflection journals, and observation. Results show that contest participants' motivation is affected by feedback from significant others (teachers and peers), the monitoring of one's personal performance, and the collectivist mindset of Chinese culture. Moreover, the pursuit of personal excellence and failure avoiding strategies enable the participants to achieve the shared goal of the team. The aforementioned factors intertwined with one another and became a great impact on their motivation. Pedagogical implications for educators wishing to train learners in future contests are provided.