Abstract: An analytical method is developed to analyze the torsional response of a single pile embedded in layered ground. The fundamental solutions for displacements and stress components of the layered soil due to unit internal ring shear loading are first derived with integral transforms and transfer matrix method. These solutions are then combined with the displacement compatability between the pile and the surrounding soil to analyze the torsional behaviour of a single pile. Comparisons with existing numerical solutions for the special case of a homogeneous isotropic elastic half space are presented to confirm the validity of the proposed method. Selected numerical results for the torsional responses of a single pile embedded in a two-layered ground are also presented.