A neighborhood strengthened CSSO-RS is proposed to improve the disadvantages of the Concurrent Subspace Optimization based on Response Surface (CSSO-RS). This algorithm gives rise to an optimization between the system level optimization and subspace level optimization, which greatly improves the coordination affection between these two levels. The optimization region of this algorithm is the neighborhood of the optimal solution obtained by the subspace optimization, and all the design variables are involved in this optimization. The classical test function and an aircraft concept sizing problem were tested, and the efficacy of the algorithm was proved.