<p>Liquefying hydrogen for storage can greatly increase storage density. Nevertheless, the fuel tanks of liquid hydrogen aircraft have a larger volume than those of traditional aircraft, so the tanks require a design to reduce volume as well as weight. In this study, the effects of cryogenic fuel tank design parameters were analyzed to reduce the tank weight at preliminary design stage. The design parameters considered in this study were insulation thickness, aspect ratio (AR) of the tank cylinder, which is the ratio of the length to the diameter, tank design pressure, fuel flow rate, and total operation time of fuel. Analysis results revealed how tank weight was directly affected by the insulation thickness, tank AR, and design pressure, and indirectly affected by the fuel flow rate and total operation time of fuel. Significantly, it was found that the tank weight increases markedly in a specific tank AR range and confirmed that the design pressure for minimum tank weight can vary depending on the tank capacity (total operation time of fuel) to fuel flow rate. Therefore, based on these findings, it is possible to appropriately design liquid hydrogen fuel tanks for aircraft, as well as ships and other mobility.</p>