Abstract: The corresponding calculation formula of the axial rigidity of a single pile is deduced according to the whole curve of the top load-settlement with a linearly elastic-plastic load transfer function. Influences of the pile's length, pile's diameter, coefficient of rigidity, elastic modulus ratio of the bottom soil and surrounding soil and Poisson's ratio of surrounding soil on the axial rigidity of a super-long pile are analyzed. It can be seen that the pile's length, diameter and coefficient of rigidity have important effects on the axial rigidity.