Abstract: For all its attracktiveness due to a low hydrodynamic drag, the motion of a supercavitating vehiclein a cavity is a more complicated and paradoxical process than that of space craft. Moving in avaper- or gas- filled , the cavitating vehicle loses buoyancy------the main advantage of motion inwater, and thus need dynamic means to maintan its weight in cavity. To keep the balance andstability of the motion, supercavitating underwater vehicle need asymmetrical supercavitatingflow patterns. In order to explore the asymmetrical supercavitating flow patterns, a series ofexperiments were conducted to investigate asymmetry of ventilated supercavity's configuration.Supercavitation is initiated by ventilating at moderate flow speed. By analyzing and measuring thephotos of supercavity under conditions of various Froude number, attack angle of model andcavitator, the relations between supercavity asymmetry and the factors those arose it were foundqualitatively and quantitatively. The result indicated that whencompound parameter F_r^2(1+\sigma) isgreater than 50, the asymmetrical deformation caused by gravity is less than 5‰. Theasymmetrical supercavitating flow pattern can satisfy the requirement of supercavitating motion ofunderwater vehicle.