Assuming deep buried sand is an aggregate of randomly packed uniform spheres,the equivalent shear modulus and the formula of shear wave velocity(V s) in sand media were derived based on the the spheres-contact theory and the research results of microscopic particles elasticity.Seven influencing factors were analyzed,including porosity,saturation,internal friction angle,soil grain density,magnitude of stress,elastic modulus of sand grain and Poisson ratio of sand grain.The results were compared with the measured data,and the calculated value of V s were generally in good agreement with the measured values.This study indicates that the value of V s is mainly influenced by porosity,magnitude of stress and the elastic modulus of sand grain,and the shear wave velocity increases with the increasing of stress in high stress state,especially after the degree of density achieves 100%.