In elucidating the behaviors of pile on cyclic loading test, calculation method of axial force was examined in due consideration of non-linearity and hysteresis of load-strain relations of concrete pile. In this paper the characteristics of the load-strain relations on loading test data of three precast concrete piles were indicated, and calculation method of the axial force based on strain data of pile in the ground was proposed by means of formulating the characteristics. Then on the basis of the calculated axial force distributions and settlement data, load-settlement properties under cyclic loading were considered.
