This article presents the results of empirical research on the construction of a precursor model of the phenomenon of thermal expansion and contraction of metals in preschool children's thinking, which is compatible with the model used in science education. The research included 87 children aged 5-6. It was conducted at four stages, during which predictions and explanations for simple cases of thermal expansion and contraction were sought. The discussions with the children demonstrated that a considerable number of preschoolers are able to take advantage of their involvement in the specific teaching processes and construct a stable precursor model of the phenomenon.