The purpose of the study was to explore children's understanding of mind shown in children's play in a preschool classroom. Previous research on children's theory of mind has relied on empirical studies utilizing several tasks, such as false belief tasks. Since children's emerging understanding of self and others is a complex process of entering a community of theories of mind (Nelson, Henseler, & Plesa, 2000), it is important to expand our understanding of children's theories of mind through qualitative inquiry with contextually-relevant methods. This study was guided by the following questions: How is children's theory of mind manifested in play and social interactions with other children in a preschool classroom? How do children negotiate differences between their own and others' theory of mind in their interactions? How are children's relationships extended through their understanding of each other's theories of mind? The main tool for exploration of the study was an interpretive analysis based on data collected through participant observation, along with dialogic interviews, audio and video taping, my reflections, and review of the literature. This study of one preschool classroom presents that theory of mind is not made up of isolated constructs but richly integrated states of mind. It appeared that interplay between social and cognitive factors was more evident in social contexts. Diverse aspects of children's theory of mind were discussed through detailed descriptions and interpretations of play episodes. A new way of looking at children's theory of mind should be more qualitative, contextual, and holistic. / Ph. D.