Abstract：Sandstone is a typical sedimentary rock with bedding stratum as a result of weathering，transportation and sedimentation of clastic substances，which possess strong inherent anisotropy in deformation，energy dissipation and wave propagation. The effects of bedding inclination on elastic modulus，Poisson¢s ratio and attenuation of bedding sandstone are investigated by uniaxial cyclic loading tests. The data of 10 specimens in which the bedding inclinations are from 0° to 90° with increment of 10° are gained，and used to compute the anisotropy of the sandstone instead of the data in the directions parallel and perpendicular to the bedding stratum. Experiments demonstrate that the elastic modulus and Poisson¢s ratio of sandstone subjected to cyclic loading parallel to bedding are smaller than those of sandstone subjected to cyclic loading perpendicular to bedding，whereas the attenuation of the sandstone subjected to cyclic loading parallel to bedding is larger than that of sandstone subjected to cyclic loading perpendicular to bedding. Elastic modulus，Poisson¢s ratio and attenuation at any inclination bedding are between those in the directions parallel and perpendicular to bedding. By a transformation of the coordinate system，the equations linking the oriented elastic modulus and Poisson¢s ratio to the elastic parameters in the directions parallel and perpendicular to bedding of sandstone are obtained. The over-determined set of equations is solved by a least-square method to compute the elastic parameters by which the degree of anisotropy of elastic properties is discussed. This treatment can reduce the errors of computed anisotropic parameters；and even with large error of computed Poisson¢s ratio，its degree of anisotropy can also be estimated. The anisotropy of elastic modulus，Poisson¢s ratio and attenuation of Wuhan sandstone are 5.6%，5.7% and 5.5%，respectively. The anisotropy of Poisson¢s ratio is larger than that of elastic modulus for Wuhan sandstone.
