The major purpose of the study is to investigate a child''s conceptions of shapes. Shou-Chi(pseudo name), the participant, was a second grader. She has been interviewed seven times so that her activities about rectangles , squares, as well as triangles were video-taped, where records were transcribed into protocols for further analysis. Although conceptions of rectangles, squares and triangles seem different , resulting from analysis of protocoles, Shou-Chi''s conceptions of shapes share the following properties: (a) Shapes means configurations of objects. (b) Labels of shapes are assigned according to the viewer''s different perspectives. (c) Shapes of the same category might be labeled differently, if lengths of consecutive sides apparently differ in ratio. (d) Shapes are analyzed into their components, such as angles, vertexes, edges, and so on, but relationships among components are treated holistically. (e) Although shapes might be labeled differently by perspectives, properties of shapes remained invariant. (f) Right angles are shapes composed by vertical and horizontal lines. (g) Implicit conceptions of congruence and similarity are observed in forms of senori-motor activities.