Sandwich panels are widely used in the main structure of aircrafts and ships because of their lightweight, high strength, stiffness, durability, and corrosion resistance. The present paper proposes a manufacturing process of a carbody structure of rolling stock using a composite honeycomb sandwich panel. The panel is made of carbon/epoxy composite faces and an aluminum core. The faces bear bending loads and the core shearing load. A product is manufactured by lay-up of composite material on the mold of the product in final dimensions; then cured in a large autoclave for obtaining one body of a structure. In this study, in order to evaluate the mechanical properties of the honeycomb sandwich panel, tensile test, compressive test, flexural test and shear test of the face in honeycomb sandwich panel were performed. Impact test for the honeycomb sandwich panel was also carried out. Moreover, end compression test was conducted. The results show that the composite honeycomb sandwich panel has good properties for the carbody structure of rolling stock.