Nonlinear dynamic analysis of a reinforced concrete (RC) frame under earthquake loading is performed in this paper on the basis of a hysteretic moment-curvature relation. Unlike previous analytic moment-curvature relations which take into account the flexural deformation only with the perfect-bond assumption, the proposed relation considers the rigid-body-motion due to anchorage slip at the fixed end, which accounts for more than 50% of the total deformation, using an equivalent flexural stiffness. The advantages of the proposed relation, compared with the layered section approach and multi-component model, may be on the easiness in application to a complex structure composed of many element and on the reduction in calculation time and memory space. The use of curved unloading and reloading branches inferred from the stress-strain relation of steel and consideration of the pinching effect caused by axial force made it possible to describe the structural response more exactly. Finally, correlation studies between analytical and experimental results are conducted to establish the applicability of the proposed model to the nonlinear dynamic analysis of RC structures.