Abstract: Through the full scale static load model tests on the cast-in-situ X-shaped concrete piles and circular piles with the same cross-section area and circular p iles with the same perimeter, the distribution of pile axial force and the development of pile shaft resistance and pile toe resistance are comparatively analyzed, and the load transfer mechanism of the X-shaped piles is studied. The tes t results show that: for the X-shaped piles, the ultimate bearing capacity and the bearing capacity per unit volume of pile concrete are both 1.32 times those of the circular pile in the same area, and 0.84 times and 1.47 times respectively those of the circular piles with the same perimeter. From the view of improving the bearin g capacity of the pile and saving the amount of pile concrete, the X-shaped pile is a new pile with is high vertical bearing capacity and low cost, therefore it has the extremely high promotion and application value in soft soil foundation.