Cognitive development and sociocultural theories support the role of play and peer cooperative problem solving (CPS) in children's learning and development; nevertheless, we still lack cross-cultural studies that investigate children's CPS during play in natural classroom contexts in early childhood. A nine-month field work including ethnographic informed focal-child observations and video-stimulated teacher interviews was conducted. Preliminary findings showed a) patterns of children's CPS during play between two cultural contexts, and b) teachers' beliefs and decision-making for supporting children's CPS during play. This study not only i) develops an innovative methodological tool to study young children's CPS in natural contexts, cross-culturally, but also ii) informs teacher educators' culturally sensitive teaching and curricula development for the improvement of children's learning.