A　set　of　stress　controlled　bi-directional　cyclic　loading　tests　under　isotropic　consolidated　condition　was　conducted　for　simulating　the　cyclic　stress　induced　by　wave　loading.　The　stress　path　followed　during　the　test　in　terms　of　σd/2　and　τ　was　controlled　in　shape　of　ellipse.　The　area　bounded　by　the　elliptical　stress　path　was　kept　unchanged　while　the　amplitude　of　the　axial　and　torsional　shear　stresses　were　varied　to　study　the　effect　of　two　components　on　the　strength　and　deformation　behavior　of　saturated　loose　sand.　It　was　shown　that　the　resistance　to　liquefaction　of　saturated　sand　was　considerably　related　with　both　the　area　of　elliptical　stress　path　and　the　ratio　of　the　two　stress　components.　For　the　same　ratio　of　two　stress　components,　the　resistance　to　liquefaction　of　saturated　sand　decreased　with　the　increasing　area　of　the　elliptical　stress　path.　However,　for　the　same　area　of　elliptical　stress　path,　the　sand　might　exhibit　the　highest　resistance　to　liquefaction　at　a　critical　ratio　of　axial　and　torsional　shear　stresses,　0.　6-0.　75.　The　resistance　to　liquefaction　increased　with　the　increasing　ratio　of　σd/2　and　τ　when　the　ratio　was　less　than　the　critical　value,　and　decreased　with　the　increasing　ratio　of　σd/2　and　τ　when　the　ratio　was　larger　than　the　critical　value.　Moreover,　the　pore　water　pressure　developed　gradually　to　the　initial　effective　confining　pressure　with　transient　fluctuation　and　phase　matching　axial　load.