Abstract: A new formula for evaluating the maximum dynamic shear modulus of the sand under the anisotropic consolidation is presented by using the resonant column method. The test results indicate that the suitable form of the new formula is to use the power function to describe the relation between the relative increment of the maximum dynamic shear modulus due to the anisotropic consolidation, Δ Gm/G0 , and the increment of the consolidation ratio, kc-1, i.e., ΔGm/G0 =C·(kc-1)B. The coefficient B is far less than 1, which means the ,m ,m maximum dynamic shear modulus increases rapidly when kc is near to 1 and then increases slowly, much making a great difference from the nearly straight relation between the maximum dynamic shear modulus and kc as in Hardin and Black’s formula. The coefficient C is 0.55-0.74 for two kinds of sands in the paper, which indicates that the increase of the maximum dynamic shear modulus due to kc>1 is significantly larger than that described in Hardin and Black’s formula.