An integrated electrochromic 2D/3D display device including a first substrate; a parallax barrier unit disposed under the first substrate; a color filter unit disposed under the parallax barrier unit; a common electrode disposed under the color filter unit; a liquid crystal unit disposed under the common electrode; a plurality of thin film transistors disposed under the liquid crystal unit; a second substrate disposed under the plurality of thin film transistors; and a light emitting unit disposed under the second substrate is provided. Another integrated electrochromic 2D/3D display device including a substrate; a parallax barrier unit disposed under the substrate; and a display unit disposed under the parallax barrier unit is also provided. An adjustment of a planar image and a stereo image is performed to reduce a thickness and an assembling cost of conventional display devices.