A liquid crystal display apparatus which enables a user to recognize positions and boundaries of light source blocks, a method for controlling the same, and an image display system are provided. The apparatus comprises a liquid crystal panel; a backlight which has a plurality of light source blocks and which radiates light onto the liquid crystal panel; a generating unit which generates boundary image data which indicates a light source block area as an area corresponding to each of the light source blocks on the liquid crystal panel; a combining unit which combines image data to be inputted and the boundary image data; and a display control unit which displays composite image data combined by the combining unit on the liquid crystal panel.