In this paper, a novel robust design approach is proposed to design the robustness of the nonlinear system under large uncontrollable variation. First, a variable sensitivity approach is proposed to formulate the nonlinear effect into the variable sensitivity matrix. Then, a variable sensitivity-based robust design is developed to minimize the variable sensitivity matrix so that the influence of the uncontrollable variation to the performance will be minimized. Since the proposed robust design considers the influence of the nonlinear term in a large design region, it can effectively improve the robustness of the nonlinear system despite large uncontrollable variation. Simulation examples have demonstrated the effectiveness of the proposed design method. Copyright © 2010 by ASME.