Stability is the principal aspect that characterizes underground storage, especially if it is a salt cavity. For this reason, it is important to examine factors that effected the most stability. Cavern geometry, depth and geothermal temperature are among them. At first, sensitivity analysis was made using the analytical method in order to compare the steady state volume loss rate experienced by spherical and cylindrical cavern in two reference cases, which are Etrez (France) and Salina (USA). As expected, volume loss rate increases as internal pressure drops. The comparison showed that Etrez case has higher volume loss rate for shallower cavern, for both cylindrical and spherical; for deeper cavern, the situation is reversed and Salina case shows a faster closure rate.