A liquid crystal displaying panel is formed of a number of pixels in the horizontal and vertical directions based on a PAL system of many horizontal scanning lines. A polarity reversing circuit reverses the polarity of an input video signal at a predetermined period and a signal feeding circuit samples the video signal reversed in the polarity and holds it. The signal feeding circuit feeds the output to the respective data lines of the liquid crystal panel and can feed the output corresponding to the data lines of an NTSC video displaying region by a switch to the data lines corresponding to the blank part other than the NTSC system video displaying region. A scanning circuit feeds a driving signal to the respective gate lines of the liquid crystal displaying panel and can feed the output corresponding to the gate lines of the NTSC video displaying region by a switch so that, when the NTSC system is selected, an intrinsic NTSC video will be displayed in the displaying region and the NTSC video will be displayed also in the blank part. That is to say, by alternately driving the liquid crystal of all the pixels, a video of the same picture quality can be displayed in the PAL system and NTSC system without deteriorating the liquid crystal.