A method for implementing resources reservation in an access configuration mode in an NGN, including: when a subscriber accesses a network, an NAAF sending a resources request message to a resources mediation PDF; after receiving the resources request message, the resources mediation PDF making an admission decision according to network operator policy rules and availability of resources, send an admission installation command to a BGF, setting and keeping the corresponding admission decision parameters information in the BGF. Thus, the BGF performs packet forwarding operations as classifying, marking, shaping, and discarding on the user traffic entering the network according to the admission decision information so as to ensure the QoS class required by the user. Therefore, an applicable solution for implementing resources reservation in the access configuration mode in the NGN is provided.