As a basic study for future lunar/planetary exploration missions, a series of model tests of shallow footing systems on a simulated lunar soil were conducted in partial gravity fields. Moreover, to rationally explain the dependence of ultimate bearing capacity on gravity, theoretical evaluations were attempted in the framework of the upper bound method. The proposed calculation method not only makes it possible to quantitatively correlate the failure mode with dependence on gravity, but also may allow us to predict the ultimate bearing capacity in the lunar surface environment.