To provide a two-dimensional code and its formation structure, which allows both of visually readable identification characters and an optically readable identification code to be displayed in a small space.

The two-dimensional code 11 has a square code area, defined by three positioning symbols 2, arranged in corners corresponding to three vertices. A character area 4 for displaying an identification character 3 is formed in the corner, where the positioning symbol 2 is not arranged in the code area. The code area comprises 21×21 cells, where the size of the character area is 9×9 cells. In a remaining area (data area) 6, excluding the character area 4, by arranging the positioning symbols 2 and the timing pattern 5, data cells are arranged two-dimensionally, each cell is either bright or dark colored, and thereby an identification code is displayed. The identification character 3 is visually read with human eyes, and the identification code is read by an optical reading device.