Theoretical and experimental study of probable mechanisms of child's imagination is presented. The hypothesis is: child's imagination may be described as an entity of the following mechanisms - reproduction (discretion) of the whole image by its part which is followed by disintegration of this whole into its elements, on the basis (if one of which a new entity is created if necessary. An original technique "Puzzle blocks" was used to prove these assumptions. In the course of experiments 4 strategies were observed correlating as it seems with the levels of child's imagination's development. All the strategies have common features due to common mechanism of imagination operations.