The technologies of virtual assembly for combine harvester chassis parts were studied and the virtual reality assembly was realized. The 3-D models of the combine harvester chassis parts were created by Pro/E, and then were converted into the virtual reality models with the model conversion interface between the CAD system and the virtual assembly system. The assembly model composed of assembly object information, assembly hierarchy information and assembly constraint information was built in the virtual reality system. By using virtual reality system and the ART tracking system together, the interactive assembly of combine harvester chassis was achieved. At the same time, the interchangeability assembly method, the usage of assembly tool, and the records and optimization of assembling path were studied. With the EON software and its secondary development tool, the virtual assembly experiment of the combine harvester chassis parts were carried out. The result indicated the methods mentioned above could work availably.