In this study, bubble formation in high pressure systems is investigated. The volume and shape of bubbles formed at an orifice submerged in liquid under high pressure are experimentally measured, To elucidate the bubble formation mechanism and to estimate the bubble volume in high pressure systems, a non-spherical bubble formation model is used, When the volume and shape of the bubble are calculated by the model under highly pressurized conditions, surface tension should be considered as a function of system pressure, The volume and shape of bubble are estimated relatively well by the model, including the change in surface tension with the system pressure.