The purpose of this study was to examine toddlers' emotional reactions to separation from their primary caregivers through the observation on a group of toddlers (18-30 months old) at a university preschool classroom. Interactional ethnography with ethnographic perspective and sociolinguistic discourse analysis was used as the theoretical framework to investigate individual children's behavioral patterns from an insider's perspective. The focus was on the multiple interactions between and among the participants in this specific cultural setting. The observation on children and the interviews with the informants supported most previous studies on the interaction between children and parents and its impact on young children's transition from home to school setting. Additionally, different perceptions from teachers, parents and grandparents were compared on how to help young children deal with the stress during transition time. The finding of this study contributes to the literature that younger children (infants and toddlers) are able to go through a smooth transition in a high-quality early childhood program. (Contains 4 tables and 3 figures.)