Each structure needs a vital part to be stable on the ground, which is called foundation. In recent years, Piled rafts, which is a combination of raft and pile group foundations, has been used mostly for tall buildings and towers with great heights. Load carrying in this type of foundation is performed by soil, piles group and raft where role of each component in load capacity should be considered. There has been numerous studied on total and differential settlement, maximum bending moments and the contribution of load carrying of the piles in this specific type of foundations. Previous studies indicate that in presence of the vertical load, increase in load capacity and decrease in settlement will happen in tapered piles in relate to cylindrical piles. In this study the effect of increasing of the taper angle, length of the piles, changes in the pile arrays, concentration of the pile number in the center of the foundation and increasing in the thickness of the raft in the homogenized sand soil has been considered. In order to perform this study, FLAC3D software and finite difference numerical method (FDM) were used. Load capacity, settlement of the center of the foundation, the contribution of load carrying of the piles and the maximum bending moment of the foundation in the range of allowed settlement for the construction regulations were obtained using the resulting charts and analyses. Taper angle of 1.20 was chosen as the optimum taper angle for the piles. The presented results showed that a change in each of the effective factors such as increasing of the taper angle for the piles, length of the piles, changes in the pile array, concentration of the pile number in the center of the foundation and increasing the thickness of the raft can play a beneficial role in all or some of the design criterions (such as load carrying, settlement of the center of the foundation and differential settlement, the contribution of the load capacity of the piles and the maximum of the bending moment). Increasing the length and number of the piles has played a major role in decreasing the differential settlements. The results have shown that the optimum spacing between the piles is about 4 times of the diameter of the pile. Keywords: Piled raft foundation, tapered piles, static vertical load, finite difference method (FDM), differential settlement, load-settlement curve, maximum bending moment