A review of current computer-aided technologies in design and product development, the evolution of CAD modeling, and a framework of multi-volume CAD modeling system for heterogeneous object design and fabrication are presented in this paper. The multi-volume CAD modeling system is presented based on nonmanifold topological elements. Material identifications are defined as design attributes introduced with geometric and topological information at the design stage. Extended Euler operation and reasoning Boolean operations for merging and extraction are executed according to the associated material identifications in the developed multi-volume modeling system for heterogeneous object. Application example and a pseudo-processing algorithm for prototyping of heterogeneous structure through solid free-form fabrication is also described.