Abstract: In this paper, the conception and development motives of the latest hot topic:IN (intelligent network) are introduced. its kernel ideas, basic architecture and related standards are briefly described. Further, principal practical values are given and its five latest research items are introduced as follows:the integration of IN and mobile communication network, the integration of IN and B-ISDN, the integration of IN and INTERNET, the interworking between ins and the integration of IN and TMN (telecommunication management network). A conclusion is also drawn that it is of significance to develop INs in china.