Rotational shear has been defined in theory as a class of loading condition under which the second invariant, J 2 D , of the deviatoric stress tensor is kept constant during shearing. While rotational shear as strictly defined in theory is seldom seen in real life, its characteristics do exist in many practical loading conditions. Seismic loading is one example. A limited number of undrained tests on saturated sand have shown that rotational shearing yields more pore pressure than other shear paths of the same J 2 D magnitude. By intuition, this experimental finding seems to suggest that sand subjected to loading bearing the characteristics of rotational shear may have lower resistance to liquefaction than that under conventional unidirectional shear. However, in contrast to the intuition, a careful examination of the field stress and boundary conditions indicates that rotational shearing may have very little impact on the liquefaction resistance of natural soil deposits. This paper presents the theoretical evidence and numerical results that support the conclusion.