This paper presents a web-based information retrieval system for 3-D graphic data. We describe a 3-D database system and its web-based user interface supporting semantics of 3-D objects. Our system offers a content-based retrieval for 3-D scenes that few graphic database systems are capable of. The user can pose a visual query involving 3-D shapes and spatial relations on the web interface. The data model underlying the retrieval system models 3-D scenes using domain objects and their spatial relations. An XML-based data modeling language called 3DGML has been designed to support the data model. It offers an object-oriented 3-D image modeling mechanism that separates low level implementation details of 3-D objects from their semantic roles in a 3-D scene. We discuss the retrieval system and the data modeling technique in detail. We believe our work is one of the earliest efforts to take advantage of XML for 3-D graphics.