Experimental investigations on cyclic behaviour of reinforced concrete (RC) structures have demonstrated that, bidirectional flexural deformation is much more, compared to unidirectional responses separately. Biaxial lateral load interaction, therefore, has a significant role on the dynamic responses of structure. The present paper projected a new formulation of the biaxial forcedeformation model, accounting strength and stiffness degradation in a rather simplistic manner. Also the modelling scheme dose not requires much computational rigour. The present effort is based on yield surface approach of biaxial modelling scheme. The validity of the proposed model is appraised through available biaxial test of RC column. Compared to other existing models, present model requires simple input parameters and the prediction of hysteretic responses are quite faithful. In the RC containment structures, which are the prime concern to the safety of nuclear power plant, this model may pertain to evaluate the hysteretic responses with fair accuracy during seismic loading. Copyright © 2005 by ASME.