Electrohydraulic forming is one of the high-speed forming processes that can deform a sheet material with a speed higher than 100m/s. When a material is deformed under this condition, it has improved formability due to high-strain rate effect. Therefore, in this study, to confirm the enhancement of formability of an Al 6061-T6 sheet, electrohydraulic forming experiments were carried out using free-bulging die. By comparing the strain distribution of deformed material in electrohydraulic forming process with the quasi-static forming limit diagram, it was verified that the material has more higher strain values than the quasi-static forming limit curve without any crack or wrinkle, which means that the formability of the material in high-speed condition is improved. Furthermore, to observe the deformation mechanism of the material in more detail, finite element analysis was conducted in LS-DYNA program. With the improved formability, it is expected to deform an Al 6061-T6 sheet into the complex shapes that is not created in conventional quasi-static forming processes.