This paper describes a self-organizing system based on concept of emergence. In the early design process, the conventional method for deriving diverse design solutions depends on the designer's experience and knowledge. Therefore, an engineering design method, which can derive diverse design solutions, is necessary for designers. In this research, we focus on an emergence phenomenon which creates diverse organism, and a self-organizing system based on concept of emergence is demonstrated for deriving diverse solutions. First, we explain the concept of "emergence", including phenomena in nature. Moreover, a potential of emergent concepts in design is indicated through comparison of emergence and design processes. Moreover, we propose the emergent design system as a self-organizing system and apply the proposed system to a two-dimensional cantilever beam design As a result, diverse design solutions, which have different features and satisfy the design conditions, are derived. Additionally, a possibility for supporting designers in the early design process is indicated.