CTBA(Coupled Torsion Beam Axle) has been adapted as the rear suspension of a compact car. Because that has the advantage of cost and weight in comparison with multi-link type. But CTBA has the disadvantage in vehicle stability to become oversteer occurring toe-out of the rear wheel when cornering and braking. In this study, we suggested CTBA Geometry Compensation System to overcome the disadvantage of CTBA. We predicted braking and cornering vehicle performance from proposed equation and numerical simulation. And also, the results were compared to objective and subjective evaluation in vehicle.