The structural model for midship section is within the scope of STEP AP218.It supports to represent the ship structural models,but shipyards and classification societies exchange the information via 2D drawings.To convert the 2D information into the ship structure models of STEP AP218,we analyze the 2D midship section information of KR-TRAS of Korean Register of Shipping, and add the transverse members information.We also define the mapping table with mapping relationships between two data structures.With this mapping table we develop the translator for midship section.We visualize the translated 3D ship structure model using a STEP viewer.The ship structural model can be shared between different design departments,and used for the lifecycle through design,analysis,and maintenance.