Abstract: The negative friction problem of single pile under the action of the surface circular load is studied by Biots consolidation theory and integral equation method. By using integral transform methods, the fundamental solutions of circular load in the interior and on the surface of the half space are established in this paper. The second kind of Fredholm integral equation of the single pile under the action of circular load in saturated soil is obtained by using the fundamental solutions. The integral equation can be simplified by means of Laplace transforms methods. By the numerical solution of the integral equation and the corresponding inverse integral transforms the displacement, axial force and the shear stress of the pile and pore pressure along the pile axis are obtained.