Wing is the basic guarantee of the plane in flight, because the aerodynamic force is produced by the wing when the plane is in flight. The wing box is the main support component of the wing, undertaking all the loads from the wing. So the structure of wing box is very important to the wing even the whole plane. A good design of wing box structure is not only ensure the aerodynamic force that the plane is needed and the systems in the wing when the plane is in flight, but also have a light structural weight by making full use of the property about the materials. So the technology of the structural optimization is used widely. This study summarizes the work of structural optimization of the wing box. The introduction including the size optimization about different layout of the wing box, different aerodynamic press center of the wing, different location of the pylon, and the different location of the wing box, make the analysis about the factors that affect the structural weight of the wing box, and make basement for the preliminary design course.