A finite difference method for solving steady natural convection problem in cubic cavity is presented. The general method is pseudo-unsteady and uses an implicit finite differences scheme for the time integration. The generalized Alternating Direct Implicit (ADI) procedure is applied to reduce the problem to succesive solutions of 1-D. The spatial discretization uses finite difference approximation and stuctured mesh is employed. Difficulty related to the pressure can be overcome by using artificial compressibility method. The velocity and temperature components are located on the corner of cell, and pressure components are located on the center of cell. This arrangement couples the velocities and pressure strongly, so the spurious pressure mode can be supressed. For low Rayleigh Number (ra=2x10³ 10), the results have a quite good agreement with the jacob's correlation.