In order to investigate a parctical treatment of undrained shear strength of soils of intermediate grading between sand and clay, a series of unconfined compression and unconsolidated-undrained triaxial conpression tests are performed on soil samples for wide range of grading. The samples are prepared by comsolidating slurries which are made by mixing sand and clay with various proportion. Test results show that, as the clay fraction of sample decreases, the rate of increase in compression strength with confining pressure increases, and the unconfined compression strength becomes relatively smaller. These phenomena can be explained by reduction in degree of saturation due to release of consolidation pressure in the course of sample preparation. Based on the test results, the measured value of unconfined compression strength of soils having intermediate grading between sand and clay can be corrected for stress release in the in-situ soil sampling. This correction requires the overburden stress in term of total stress and two kinds of correction factors, which are determined by the clay fraction or plasticity index. Application of this correction is limited to the soils of clay fraction of more than 10%.