The thesis is focused on phenomenon of free play in preschool age children. Theoretical part of this work explains game itself and its context. Focus is aimed at capturing specifics of preschool age child's play, its importance for kids and division to several types. Major part of this thesis also explains concept of free play in preschool child development. Practical part contains research investigation of free play in children from three to four age in kindergarten. Goal of this investigation was set as follows: give description at free play phenomenon in preschool aged kids in preschool environment. Chosen methods for this research were observation together with non-structured interviews with participants of research - the kids themselves. Research findings describes prevailing types of play and themes that children chose during the free play. Results indicates which toys and tools children use to play with and what kind of relationship they had with them. In addition, children's interactions with others are described and also another features of the free play of preschool children. Key words phenomenon of play, free play, preschool child, preschool enviroment