Abstract: The torsional vibration of a single pipe pile in radial heterogeneous saturated soil was investigated by the theory of porous medium. The saturated soil around the pipe pile was divided into undisturbed area and disturbed area, and the torsional dynamic model of a single pipe pile in radial heterogeneous saturated soil was established. Using the mathematical method, the torsional vibrations of pile core saturated soil, the undisturbed area and disturbed area of saturated soil around the pile were solved by Novak thin layer method and the method of multi-zone, the recurrence formulas of torsional shear stiffness of each zone were obtained by considering the boundary conditions of the soil and the continuity conditions of each zone. The torsional dynamic equation of a single pipe pile in radial heterogeneous saturated soil was established, and also obtained the torsional complex stiffness at pipe pile head. Comparative analysis and discussion were investigated by numeral example, the results indicated that the radial heterogeneous properties of soil around pile need to be considered for studying the torsional vibration of a single pipe pile in saturated soil, and the influence of liquid phase should not be ignored at high frequency, and in the design of pile foundation, the geometric size of pipe pile should be paid close attention to.