A head mounted display including a main strap, a display part, an adjusting mechanism, a forehead pad, a plurality of holders and a lace is provided. The main strap surrounds a user's head. The display part is connected to the main strap and corresponds to the user's eyes. The adjusting mechanism is disposed on the main strap. The forehead pad corresponds to the user's frontal bone. The holders are disposed on the main strap and the forehead pad. A path of the lace in sequence passes through a retractable portion, a portion of the main strap near a first side of the display part, a first side of the forehead pad, a fixed portion of the lace, a second side of the forehead pad and a portion of the main strap near a second side of the display part. The adjusting mechanism connects the retractable portion and is adapted to adjust a magnitude of tension of the lace at the retractable portion. The lace is fixed at the main strap and the forehead pad by the holders.