Abstract: With the economic development,“prosperous economy”era is becoming obvious so that the approaches applied in marketing have also changed accordingly.The Long Tail Theory serves as a theoretical basis to cope up with the changes.This paper analyzes the origin of the Long Tail Theory and discusses the complementary relationship between the Long Tail theory and the traditional“80-20”rule(Pareto principle).In addition,the author explores SME's networking survival mechanism under the Long Tail Theory based on the main target of the theory-the small-and medium-sized enterprises as well as their application of the Internet.Finally,the paper demonstrates SME's networking strategy for survival under the Long Tail Theory from three aspects:with a large-scale custom to reduce the cost of purchase for the clients;with targeted online advertising to filter information for the clients; with a well-maintained good interaction with other professional service-providers to provide an effective service system for the clients.