Abstract: A method for collecting network usage data of a user in which access device in the network authenticates and authorizes the user, and an AAA server records the user's network resources information authenticated and authorized. IN addition, during network access a router records network usage information and sends the network usage information with UDP messages to an NSC, the NSC aggregates the collected network usage information, the association analysis server performs real-time association analysis for the aggregated network usage data and user network resource information uploaded from AAA server to obtain detailed network usage data of the user.