Piles may be subject to axial and lateral loading during their service life. While axial loading is usually more of the main concern, lateral loading may also cause severe damages. In general, the behavior of laterally loaded piles is much more complex than that of axially loaded piles, since large deformation of the piles and significant soil nonlinearity are involved which cannot be modeled closely with conventional analytical or numerical methods such as finite element technique. In this study, Discrete Element Method (DEM) was employed to investigate the pile-soil response in laterally loaded piles in sands. DEM model was built up, and the container size was determined by cavity expansion theory. Series of simulations were carried out. Influences of pile installation methods, pile surface roughness, particle size distribution, soil relative density and particle shape to the laterally loaded pile response were examined. It is found that, according to this study, DEM results produce comprehensively reasonable simulation results compared with Reese’s (1974) practical p-y curve method. However, lower initial p-y curve stiffness was found in DEM results than the practical calculation proposed by Reese (1974). And other findings include that driven piles show higher lateral resistance than drilled piles. Piles with rough surface also show higher lateral p-y curve stiffness and ultimate resistance than those with smooth surface. Particle size distribution and particle shape would also affect the pile-soil response, but not as much as the influence of the relative density of the soil.