The present invention relates to an illuminant human interface device, and more particularly to a housing structure assembly. A housing structure assembly for carrying an input device includes a housing structure, a light source and an input device. The housing structure includes an input device carrying area and a light-transmissive layer. The light-transmissive layer has a light incident plane and a light exit plane, and the light exit plane is located in the input device carrying area. The light source is adjacent to the light incident plane, and the light source emits a light ray. The light ray enters the light-transmissive layer through the light incident plane and then exits the housing structure through the light exit plane. The input device is located on the light exit plane. The housing structure for carrying the input device provides a backlight for the input device after being combined with the light source, thus reducing the repair and replacement costs of the input device.