Abstract: In order to get a perfect ventilated supercavity with controllable shape and reducible drag, the experiments have been done in a ventilated cavitation tunnel to study the relationship between the cavitator parameters and the ventilated supercavity shape. Experimental results showed that the cavitator diameter plays an important role on the ventilated supercavity developing. Under the same conditions of the fluid parameters, the bigger the cavitator diameter is, the easier the cavitation is and the bigger the ventilated supercavity size becomes. Fineness ratio of ventilated supercavity is closely related to cavitator diameter. The ratio of cavitator diameter to the attached body diameter is unfit for choice. The contour of cavitator is also an important parameter, for instance, under the same conditions of the fluid parameters the blunt reverse angle cavitator is easier to form supercavity than conic cavitator，and the conic cavitator with the smaller cone angle is much harder to form ventilated supercavity than the one with a bigger cone angle. Besides, the experimental results of disk cavitator have been compared with theoretical results in the paper, and the main patterns agree.