Recently, semantic based 3D object retrieval has been paid more attention to because it focuses on obtaining the retrieved objects in a machine understandable and intelligent manner. In this paper, we propose an approach for semantic based annotation of 3D shapes. To enable semantic based annotation, the method for object segmentation decomposes 3D objects into meaningful parts semi-automatically. Furthermore, each part can be regarded as a 3D object, and further be semantically annotated according to ontology vocabulary from the Chinese cultural relics. Such a segmentation and annotation provide the premise for the future retrieval of 3D shapes.