A method of controlling a run mode of a video signal recording/reproducing apparatus is provided. More particularly, a method of controlling a special playback mode of a video signal reproducing apparatus, by rejecting a special playback key input during comparison of program classes in an initial playback mode, and restricting run of a special playback mode while a video signal loaded with program class data is being reproduced, is provided. The special playback key command, which is input while the video signal with program class data is being reproduced, is refused, thereby preventing pictures from being output regardless of program class, because the program class cannot be exactly detected in a special playback mode.