Abstract: Based on analyzing the variation of representative academic viewpoints, the developing trends of design studies, especially on the theme of design science are given. The trends present as changing from paying attention to the methodology of design to investigating the knowledge behavior in design, and from studying the design of material products to considering that either the design of material products, mental products or social products should follow similar design axioms. Our further studies show that the design is essentially a process of knowledge flow, knowledge integration, knowledge competitiveness and knowledge evolution, the influence on the design competitive power of the knowledge flow in society is greater than that in the brains of designers (or teams) especially in innovation and creation. Successful designs need not only process knowledge but also constitution knowledge and then arise the problems of providing knowledge and utilizing knowledge efficiently in design. Design is not only a technical issue but also a very influential social issue, and therefore there are common tenets which must be followed in all designs. On these bases, a requirement-function-structure-behavior (RFSB) framework of design is in progress. Good results have been obtained in the algorithm of integrating function knowledge, and there are still difficulties in integrating structure knowledge. Main problems come from no appropriate scheme because of the complexity of modeling structure knowledge, which requires human participation.

Key words: design, knowledge, innovation, design science, requirement-function-structure-behavior (RFSB) framework