Abstract: A traffic monitoring system enabling a manager to manage a plurality of traffic monitors in a centralized manner with a desired specification and to effectively utilize a traffic analysis result of each traffic monitor for network management is provided. The manager 1 loads a management application program to the manager itself and executes the program (S1). The manager 1 transfers the management application program to each active monitor 2 to allow the management application program to be executed (S2 and S3). Each active monitor 2 provides an analysis result to the manager 1 in response to a request (S4) from the manager 1 (S5). Each active monitor 2 stops a packet analysis program in response to a request (S6) from the manager 1 and unloads the packet analysis program. After collecting the analysis result, the manager 1 stops and unloads the management application program (S8).