Abstract: A method of automatically adjusting a CRT color monitor screen and a CRT color monitor are provided in which the horizontal position and size in a horizontal frequency of 100 kHz or so are adjusted at an acceptable accuracy thus reducing the overall cost by steps of examining with a comparison circuit 6, a one-shot circuit 7, and a microcomputer 9 whether a location determining pulse overlaps with a synthetic signal or not while shifting the phase of the location determining pulse in relation to a horizontal synchronizing signal HD, detecting the location of picture signal part of a video signal relative to the horizontal synchronizing signal HD from the result of examination, and automatically adjusting the horizontal position and the horizontal size on the screen in accordance with the result of detection.