Due to rapid development in the past decade, air transportation system has attracted considerable research attention from diverse communities. While most of the previous studies focused on airline networks, here we systematically explore the robustness of the Chinese air route network, and identify the vital edges which form the backbone of Chinese air transportation system.Specifically, we employ a memetic algorithm to minimize the network robustness after removing certain edges, and hence the solution of this model is the set of vital edges. Counterintuitively,our results show that the most vital edges are not necessarily the edges of the highest topological importance, for which we provide an extensive explanation from the microscope view. Our findings also offer new insights to understanding and optimizing other real-world network systems. Due to rapid development in the past decade, air transportation system has attracted considerable research focused on airline networks, here we systematically explore the robustness of the Chinese air route network, and identify the vital edges. which form the backbone of Chinese air transportation system.Specifically, we employ a memetic algorithm to minimize the network robustness after removing certain certain, and therefore the solution of this model is the set of vital of the heart. Counterintuitively, our results show that the most vital edges are not necessarily the edges of the highest topological importance, for which we provide an extensive explanation from the microscope view. Our findings also offer new insights to understanding and optimizing other real-world network systems.