Abstract: Comparisons of shear strength between the saturated and unsaturated sandy silt were shown based on the measured shear strength using a modified direct shear device,and shear strength was predicted using the saturated soil properties and soil-water characteristic curve(SWCC) for the sandy silt.It was illustrated that the saturated shear strength was less than the unsaturated shear strength,and the unsaturated shear strength increased with increasing matric suction.It was shown by this study that properties of the saturated-unsaturated fine-grained soils were affected by physical conditions and the stress condition in the field.