This study examined how teachers’ beliefs in emotions, as helpful or hindrance factors, influenced their reactions to children’s negative emotions. The researchers collected data through an online survey of 240 early childhood teachers in South Korea. Results revealed that teachers with firm beliefs regarding emotion as helpful (emotion-help belief) exhibited a higher degree of supportive reactions to children’s negative emotions. Conversely, teachers with firm beliefs regarding emotion as a hindrance (emotion-hinder belief) showed more unsupportive responses to children’s negative emotions. This study is significant because it is the first attempt to suggest teachers’ beliefs about emotions as helpful or hindrance determinants as a predictive factor in their emotion socialization practices. The findings indicate the need for teacher education to strengthen teachers’ positive beliefs about emotion. Such teacher education would, in turn, equip them to express more supportive reactions upon encountering children’s negative emotions. Ultimately, this will promote emotional development and build resilience in the COVID-19 pandemic generation, helping them overcome the lack of emotional development caused by the crisis.