A bi-display mode liquid crystal display comprises a top and a bottom transparent substrate that are arranged in a parallel way, and between the two transparent substrates are a liquid crystal layer, a semi-reflector and a color filter sequentially, in addition, a top and a bottom polarizer are set on the outer surface of the top and the bottom transparent substrate respectively; by setting the semi-reflector upon the color filter, it makes the light not pass through the color filter and increase the reflection rate. Therefore, the present invention not only provides a reflective mode of high brightness gray scale display, but has a transmissive mode of beautiful color, and has the advantage of power saving and easy to use.