Using GDS stress path triaxial apparatus, the isotropic consolidation tests for rootless soil and root-soil composite were carried out respectively, and then for different spherical stress, a series of constant p strees path drained triaxial compression tests were also done. Based on K-G model,the influ- ence laws of root-content of root-soil composites upon bulk modulus, volume strains, shear modulus and shear strains were discussed. The research shows, along with the increase of root-content, the bulk modu- lus and the shear modulus of root-soil composite are all enhanced remarkably, and the...