A dual liquid crystal display device includes a transmissive liquid crystal display panel; a reflective liquid crystal display panel formed on the same substrate as the transmissive liquid crystal display panel; a first light guide block disposed under the transmissive liquid crystal display panel and having dot patterns formed on a first surface thereof; a second light guide block disposed under the reflective liquid crystal display panel and having V-grooves formed on a first surface thereof and dot pattern formed on a second surface thereof; a light source disposed adjacent to the first light guide block; and a housing in which the transmissive and reflective liquid crystal display panels, the light source and the light guide blocks are seated, the housing having an opening to correspond to an image display surface of the reflective liquid crystal display panel.