A parametric study is carried out to establish the effect of different geometric parameters on the design of cruciform specimen and a suitable geometry is proposed for studying the biaxial behaviour of glass CSM reinforced polyester composites. Cruciform specimens are fabricated and subjected to equi-biaxial loading using an inplane biaxial test rig. The experimental observations confirmed the predictions of numerical analysis that the failure is governed by raised stresses near the transition zone rather than the biaxial stresses in the gauge area.