The present invention discloses a performance management system, apparatus and method between a Residential Gateway (RG) and a Broadband Remote Access Server (BRAS), the method thereof includes: configuring an OAM IWF for the protocol conversion between the performance management message of the Asynchronous Transfer Mode (ATM) Operation, Administration and Maintenance (OAM) protocol or the point-to-point Ethernet OAM protocol and the performance management message of the service layer Ethernet OAM protocol in a Digital Subscriber Line Access Multiplexer (DSLAM), when the performance management is performed in a broadband IP network, after the OAM IWF configured in the DSLAM performing the protocol conversion of performance management message, performing the end-to-end performance management between an RG and a BRAS according to the performance management message with the converted protocol. This invention can not only enhance the accuracy of the statistics of the traffic flow, but also enhance the accuracy of the SLA test.