For a safety estimation of complex structural body models, definition of geometric parameters such as a volume and center of volume is essential. Thus, it should change modeling information of face structure to B-rep or CSG form for definition of geometric parameters through each section categorization on the commercial CAD systems. But, complex structural body models can cause error while it is transformed to B-rep or CSG or too much time is spent for each face selection. And, CAD system using in almost ship yard is uncomfortable to input offset information as manual to define for each section volume, geometric parameters and then that CAD system is outside program which is paying license fee every year. Therefore, this research has developed automatic system which calculate geometric parameters each section and classify each section of complex structural body models without limitation for solid modeling and section information.