Two computer programs were reviewed and evaluated, one for linear analysis (LA) and the other for non-linear analysis (NLA), to identify the most appropOate analysis type for flexible pavement structural analysis. The programs were three-dimensional (3-D) finite element (FE) programs called SAP90 and ANSYS5.3. The comparison items were the maximum surface deflection, the maximum' vertical compressive strain at the top of the subgrade and the maximum horizontal tensile strain at the bottom of the asphalt concrete (AC)'lkOr, which are the most commonly used criteria for pavement design. In addition to these items, maximum tensile stress in AC layer and vertical stress distribution alort the pavement depth were used as the basis for comparison. Three load conditions include horizontal forces (HF) were applied to the flexible pavement models. Non-linear analysis was found to be more realistic for flexible pavement analysis. It satisfied the surface boundary condition and gave more acceptable results when studying shoving and vertical stress distribution under loading center.