This paper aims to study the lateral pressure developed on a row of piles in clay slopes for different parameters. Extensive numerical models of homogeneous slopes with piles were carried out to investigate the effect of piles length, piles location, piles diameter, slope angle, piles spacing and shear strength of clay soil on the distribution of lateral pressure acting on piles in slopes. The study was carried out using (2D PLAXIS, version 8.2) and (3D PLAXIS, version 2010) programs. In the analysis, elastic perfectlyplastic Finite Element Models based on Shear Strength Reduction Approach were used. The results were discussed and presented in terms of lateral pressure versus piles length at different cases. Moreover, the comparisons between the lateral pressure distribution using the FEM and that estimated using other methods were performed.