1. An optical tomographic imaging system, comprising: a tomographic image acquiring unit for acquiring a tomographic image by scanning an object to be inspected with measuring light; a two-dimensional image acquiring unit for acquiring a two-dimensional image of the object to be inspected; and a display control unit for controlling a display unit to display both a thumbnail image of the tomographic image and a thumbnail image of the two-dimensional image, wherein the display control unit causes the display unit to overlap a schematic diagram of a scanning locus for scanning the eye to be inspected by the tomographic image acquiring unit on the thumbnail image of the two-dimensional image, and wherein the display control unit is configured to control the display unit to display the tomographic image, and reflect on the thumbnail image of the tomographic image an image process performed on the tomographic image displayed on the display unit.