Abstract: In this paper the strength,rigidity,ductility and energy dissipation ca-pacity of columns of reinforced concrete frames consisting of precast mem-bers assembled by vertical post-tensioning under low frequency cyclic lood-ing are investigated.The effects of the compressive prestressing of concrte, the ratio of reinforcemenf and the axial load ratio on the aseismic behavior of columns are also approached by experimental study and nonlinar analy-sis.