Abstract: Using the frame of function-behavior-structure,this paper describes an explorative creative design model based on the state space expansion.By carrying out the analogy-based design on the basis of structure similarity,behavior similarity or function similarity,new structures,behaviors or functions can be passed from the source to the target design.The paper presents a design approach that modifies the state space based on the modes of match and mapping, and further points out that structure similarity, behavior similarity, function similarity,or their combinations should be applied according to the situation knowledge.