Abstract: On the basia of the experimental results of 20 specimens with rectangular transverse reinforcement which are under monotonic and cyclic loadings, the effect of the axial load and hoop retios on the ductility of columns is studied. The full-range curve of reinforced concrete members with flexure and axial loads is obtained by finite element method. After the analysis for the experimental and calculated results, a formula for the detemination of quantity of rectangular hoops in the plastic hinge region is given in this paper.