The studies regarding how the comprehension of geometric shapes evolves in childhood are largely based on the assessment of children's responses during the course of tasks linked to the recognition, classification or explanation of prototypes and models. Little attention has been granted to the issue as to what extent the geometric shape turns out to be an expressive tool that young children spontaneously use in their pictorial productions and also, whether or not methodological research approaches aimed at the examination of unprompted usage of geometric shapes in childhood may be useful regarding the study of the development of geometric thinking. This evidence provided by this study is coherent with the assumption that before starting primary education, internal representation of closed curves, quadrilaterals and triangles should have been developed by a significant number of children and, more interestingly, that young children's graphical expressivity appears liaised to their skill to depict two-dimensional geometric shapes.