In nature, soil is frequently subjected to cyclic loading under drained or undrained conditions such as traffic loads and earthquakes. In order to investigate the behavior of soil during drained cyclic loading, an accurate volumetric change measurement is one of the key issues to obtain properly the stress-dilatancy relationship. Several researchers such as Pradhan et al. (1989), Shahnazari and Towhata (2002), Nishimura (2002), De Silva (2008) among others, have conducted experimental studies to investigate the stress-dilatancy relationship of sands. However, the effect of over-consolidation on dilatancy properties of loose sand is not well understood; therefore, in this study, investigations on the stress-dilatancy relationship were conducted by performing drained cyclic torsional shear tests.