A very effective way to increase the earthquake resisting capacity of reinforced concrete frame structures is to arrange monolithic infilled wall panels (hereafter referred to as "shear walls") in the proper frames. Since the lateral stiffness of a shear wall is much larger than that of a column, the elastic behaviour of non-damaged frame structures with shear walls under seismic excitations tends to be remarkably governed by the elastic behaviour of the shear walls. Therefore, in order to analyze the elastic behaviour of the frame structures stiffened with shear walls by matrix method of structural analysis, an accurate and simple evaluation of the nodal stiffness matrices with respect to the beam-to-column connections of shear walls is required. In this paper, the fundamental components of nodal forces and nodal displacements of shear walls are clarified. And a practical calculation method for the elements of nodal stiffness matrix pertaining to shearing, flexural and axial stiffnesses of shear walls is proposed. These stiffnesses are evaluated using I-beam theory considering shearing deformation and rigid zones. The proposed shearing, flexural and axial stiffnesses will be used in the formulation of a practical nodal stiffness matrix of the shear walls with symmetric or nonsymmetric sections. The rotational stiffness of the beam-to-column connections assumed to be rigid zone in elastic framed shear walls will be presented in the follow-up of this paper of the same subtitle in the near future.