<![CDATA[Emotion regulation is an important aspect of young children’s social-emotional development that supports interaction, behavioral control, and the ability to cope with frustration. This study aimed to explore play-based learning using loose parts as a means of supporting the development of children’s emotion regulation. The study employed a descriptive qualitative approach with a case study design at KB Tunas Jaya 1, involving eight children aged 4–5 years and the classroom teacher. Data were collected through observations, interviews, and documentation, then analyzed using Miles and Huberman’s model through data reduction, data display, and conclusion drawing and verification. The findings showed that play activities using loose parts consisting of natural materials, plastic, and wood provided children with opportunities to explore materials, express themselves, and directly encounter various emotional situations. Signs of development in emotion regulation were primarily evident in impulse control and frustration tolerance, as reflected in children’s ability to wait their turn, ask for permission, try again after failure, and seek alternative materials. However, some children still had difficulty sharing materials and cooperating with peers, so social cooperation required further guidance. These findings indicate that play-based learning using loose parts has the potential to serve as a means of stimulating emotion regulation through open-ended and meaningful play experiences. The practical implication is that teachers need to provide consistent guidance as facilitators, particularly to help children manage frustration, share materials, and resolve conflicts during play.]]>
