In today’s highly volatile global market, design activities become more and more important in the whole lifecycle of product. The process of different developments should adopt appropriate modeling approaches at each stage. Different modeling technologies exert a great impact on different design stages. Therefore, modeling design is crucial to achieve success in the process of product development. This paper presents an integrated modeling of design process for product development. Its objective is to realize concurrent design towards ever-growing demands of market that has already integrated design process and production activities. It can manage to develop product towards early design activities. Different design stage model relations and activities are presented for product development. At first, the characteristics of different development stages are analyzed. The performances and attributes of product are established through considering component, constraints and environment. Second, the process of product modeling is described in detail for early design, and the time interval between the two activities is evaluated for concurrent engineering during the design modeling. Third, a promising framework is given to describe the process of design. Finally, an application example and knowledge are presented to illustrate the process of product development.