Tube hydroformig process is a new method of metal forming that has been become one of the ways of the industry. Tube hydroforming is a manufacturing process which applies controlled internal pressure and Axial feed to expand the tube to desired shapes. The main advantages are: part consolidation, weight. reduction, fewer secondary operations, and tighter tolerances. However, it has disadvantages due to many variables, such as loading paths, material formability, and tribological conditions, which limit its applicability and influence parts failure (excessive thinning, wrinkling, buckling or bursting). This process has also some drawbacks, such as slow cycle time, expensive equipment and lack of extensive knowledge base for process and tool design. In order to increase the implementation of this technology in the stamping industry, some issues need to be addressed: the preparation of the tubes (material selection and quality of the incoming tube), pre-form design and production method, application of computer simulations, selection of effective lubricants and enhancement of the tribological performance, and improvement of the formability of the tube. The main advantages are: part consolidation, weight reduction, fewer secondary operations, and tighter tolerances.This research presents ultrasonic technology as a method of improving formability and tribological conditions. The superimposing of ultrasonic oscillations was already proved to have benefits for other metal forming processes, such as reduction in the forming load and frictional stresses. No attempts have been made to investigate on the effects of ultrasonic oscillation the tube hydro forming process. Therefore, in order to advance the understanding of the mechanism of ultrasonic tube hydroforming; the finite element method was used. The ABAQUS code was used for the FEM. Finite element method was used to approximate the ultrasonic pressure and to design a set of tooling for ultrasonic process at 20 kHz .The results were compared with conventional tube hydroforming. In the axisemetric model the effects are related with the changing of the frictional conditions at the diespecimen interface. The kinematics of sliding varies and the friction force when superimposing the ultrasonic oscillations reverses the direction for every period of oscillations. Due to this friction force reversal, the friction force will oppose the forming process only during a half of the oscillations, and it will help during the other half. The result will be a decrease 15 precent in forming load and also increasing in the final tube diameter. For plain strain model in conventional process the tube is expanded under internal pressure in the presence of friction. In the ultrasonic process, vibrations are imposed on the die, resulting inalternating gaps at the die/tube interface. The gaps open and close after each oscillation. When the internal pressure is maintained, the corner radius obtained is smaller. The reduction in the corner radius was between 6.8 and 11.4%. More uniform thickness and less thinning, as well as smaller corner radius indicate improvement of the formability of the material. Key Words : finite element method, tube hydrofor ming, ultrasonic oscillations,