Based on the features of evolution of social-network-type start-up economy,this paper analyzes the status quo and difficulties of enterprises’ cluster development in China,presents three morphological characteristics of evolution of start-up economy and compares these three types one by one.Then,this paper reveals the evolutional mechanism that the “derivative economy”,with the aid of the sharing resources,grafts in the “native economy”.What is more,this paper,through the study of regional symbiosis corporate of social networks,points out the evolution mechanism from planting-based economy to focus economy of social-network-type start-up economy,and suggests that start-ups should closely depend on the social network relationship of symbiotic corporate clusters so as to avoid market risk and seek long-term development.Besides,this paper discusses the evolution mechanism from brachycephaly economy to long-tailed economy of social-network-type start-up economy.In conclusion,a theoretical framework and an evolution mechanism of start-up economy and social network are built,with the purpose of guiding the development of the regional network-based economy.