An elevator car layout information editing system 1000 includes a riding car display device 300 and a car layout information editing device 400. The riding car display device 300 stores at least one piece of car layout information showing planar layout of plural elevator cars at a transverse section of a building, displays the above car layout information, and as well carries out an editing process of the displayed car layout information according to an edition instructing signal to instruct the editing process of the above car layout information. The car layout information editing device 400 receives an editing operation for the above car layout information displayed by the riding car display device 300, generates the edition instructing signal to instruct the editing process corresponding to the received editing operation, and sends the generated edition instructing signal to the display device.