Composite shear wall is a structural component consisting of a steel plate connected using shear tabs to a reinforced concrete cover. The steel plate provides for stiffness, strength, and ductility and the concrete cover prevents the steel plate from buckling. In this paper, effects of steel plate's thickness, compressive strength and thickness of the concrete cover and spacing of the shear tabs on the characteristics of the wall in nonlinear lateral behaviour are evaluated and a macromodel substitute for the wall is developed. The macromodel is a generic lateral force-displacement rule for the wall with its characteristics as developed in this paper. Practical ranges of values are accounted for the parameters involved. Such an approach makes it possible to replace the very complicated and time-consuming three-dimensional model of the composite wall with a simple one-dimensional element following the nonlinear lateral force-displacement path as given in this paper.