Various stress-controlled drained and undrained monotonic shear tests on the Chinese Fujian standard sand of relative density 30% under complex initial consolidation conditions with different stress paths are conducted by using the soil static and dynamic universal triaxial and torsional shear apparatus. The mean principal stress is controlled unchanged in the process of tests. The coefficient of intermediate principal stress and orientation of principal stress are varied so that their influences on shear behavior and strength of saturated sand under drained and undrained conditions are respectively explored. It is shown through comparison that the coefficient of intermediate principal stress influences the stress-strain normalization relationship

but does not make obvious effect on volumetric deformation as well as pore-water pressure. Under the same initial condition

the deviator stress ratio reduces with the increase of coefficient of intermediate principal stress. The above-mentioned phenomena do not relate to the drainage condition. Orientation of principal stress also influences remarkably on monotonic shear features of sand. In drained tests

variation pattern of stress-strain relationship which is associated with the orientation of principal stress depends on shear stresses on horizontal plane and vertical plane. Furthermore

the deviator stress ratios （or the frictional angles） at phase transformation state and at peak state are all of parabolic relation with the orientation of principal stress. In undrained tests

the effective deviator stress ratio attained at peak state reduces gradually with the increase of orientation angle of the principal stress. Meanwhile

for different orientations of principal stress

the shear strength indices obtained in the tests are affected by the variation of drainage conditions.