Abstract: In a moderate-velocity cavitation tunnel, a series of experiments were conducted to investigate the shape and drag characteristics of ventilated supercavity. The ventilated cavitation number was determined by cooperating experimental results with empirical formulas. The investigation shows that the length and aspect ratio of ventilated supercavity decreased when ventilated cavitation number increased, and the drag coefficient of vehicle decreased when the aspect ratio increased. The ventilated cavitation number decreased with the ventilation flow rate by exponential law at constant velocity. More drag reduction could be achieved at smaller ventilated cavitation number and higher speed. The drag coefficient of the aft wetted area of vehicle also decreased with the ventilated cavitation number.