The invention relates to a regulation speed display apparatus of a vehicle. The apparatus causes a display device to display a detected regulation speed as a standard regulation speed when a traffic sign in a shot landscape is not a traffic sign with an auxiliary sign. The apparatus causes the display device to display the detected regulation speed as the standard regulation speed when the traffic sign in the shot landscape is the traffic sign with the auxiliary sign and the detected regulation speed is larger than an already displayed standard regulation speed. The apparatus causes the display device to maintain the display of the already displayed standard regulation speed when the traffic sign in the shot landscape is the traffic sign with the auxiliary sign and the detected regulation speed is equal to or smaller than the already displayed standard regulation speed.