The three-dimensional limit method for slope stability analysis includes the upper bound method and the 3D limit equilibrium method. The upper bound method features in its rigorous theoretical background and simple numerical procedures. The 3D limit equilibrium method is actually an extension of the Spencer Method in 2D area. It provides a more rigorous theoretical background

compared to those already published in the literature. To combine the upper bound method with the 3D limit equilibrium method

the 3D factors of safety can be reasonably bracketed in a small range. Its applications to Xiaowan deposit project show its feasibility and practicality.