Forming conical parts is one of the complex and difficult fields in sheet metal forming processes; because of the low contact area of the sheet with the punch in the initial stages of forming, too much tension is applied to the sheet causing burst occurrence. Furthermore, since the major part of the sheet surface between the blank holder and punch tip is free, wrinkles appear on the wall of the drawn parts. Therefore, these parts are normally formed in the industry by spinning, explosive forming or multi-stage deep drawing processes. In this paper, the parameters in the process of hydroforming conical parts along with using finite element simulation and experimental procedures have been studied. The punch radiuses parameters (the punch tip radius and the radius between the conical and cylinder section and their effects on the bursting and thickness distribution were investigated.