This paper proposes a 3D model generation system that outputs intermediate3D shape models between two already existing 3D models by morphing. Although there have been a lot of computer animation software, it takes a long time to create a 3D shape model even using such computer animation software. Morphing is one of the techniques used to easily create 3D models. If we have two different 3D shape models, it is possible to generate intermediate 3D shape models between them by morphing. However, there are two main problems in the morphing of polygonal models. Those are vertex mismatch and semantic topology mismatch. In this paper, the authors propose an algorithm that is free from the vertex mismatch problem and that automatically determines the semantic topology match. The proposed system based on the algorithm decomposes both two polygonal models, makes decomposed element pairs between them, and then generates intermediate 3D shape models by morphing as for the decomposed element pairs automatically.