Hydroforming is a forming technology in which a steel tube is set in a die and formed to fit a specified shape by applying hydraulic pressure from inside the tube while also applying force in the tube axial direction (axial feed). In present study, the whole process of automotive cross members simulation and development by hydroforming technology to apply high strength steel is covered. At the part design stage, it requires feasibility study and process design aided by CAE(Computer Aided Design) to confirm hydroformability in details. Overall possibility of hydroformable cross members parts could be examined by cross sectional analyses. Moreover, it is essential to ensure the formability of tube material on every forming step such as pre-bending, preforming and hydroforming. At the die design stage, all the components of prototyping tool are designed and interference with press is investigated from the point of geometry and thinning.