Abstract: As a constant evolving open complex giant system,Internet brings a big challenge on network management,as well as developing new technology and new business. One of the most important behaviour characters of Internet is emergent phenomena which attracts many researchers' attention. Investigation of Internet behaviour can help to understand the law of Internet, and play a significant role in guiding the theory and practice on effective network and user management, development of new network protocols and services. In this paper, the emergent behaviour and major features in the different layers of Internet were analyzed.Then the current researches about network emergent behaviour and related computing models were summarized. Finally the direction of investigation in this area was discussed.

Key words: Complex network, Network behaviour, Emergent behaviour, Emergent model