Abstract: The stress path followed by soil consolidation in the hydraulic filling site where the coral sand is used as the filling materials is characterized by K₀-consolidation. In order to investigate the stress-strain behaviors of the K₀-consolidated coral sand, a series of K₀-consolidation tests in a triaxial cell are carried out for the coral sands with different initial relative densities. The K₀-values of the coral sands are measured and their particle breakage indexes are evaluated. Based on the generalized Hooke's law, a nonlinear elastic model in the form of a power function is proposed to describe the stress-strain relationship of the K₀-consolidated coral sand. The functional expressions for the deformation parameters are presented, and the calculated results of the model are compared with the test curves. The results show that the stress-strain relationship of the K₀-consolidated coral sand may be expressed by a power function. With the increase of the axial effective stress, the K₀-value decreases, and the particle breakage index increases. Under the same axial effective stress, a small initial relative density corresponds to a large K₀-value and a large particle breakage index. As the increase of the axial effective stress in the K₀-state, the tangent modulus of the coral sand increases, and the tangent Poisson's ratio decreases. Under the same axial effective stress, the larger the initial relative density, the larger the tangent modulus, and the smaller the tangent Poisson's ratio. The stress-strain relationship of the K₀-consolidated coral sand with different initial relative densities within a certain stress range is reasonably predicted by the power function model. The model and deformation parameters reflect the influence of the stress path of K₀-consolidation on the stress-strain relationship.