System and method for resource admission and control is disclosed. The system for resource admission and control includes an interface unit for application function unit configured to receive service request sent from the application function unit; a policy decision function unit configured to identify the type of an access network according to the service request received by the interface unit for the application function unit and select corresponding service logic for resource admission and control according to the identified type of access network. According to the technical solutions, no matter the request for resource is made to a fixed access network defined in TISPAN, or to a wireless access network defined in the 3GPP, the policy decision function unit xPDF may identify the type of the access network and select corresponding service logic to perform resource admission and control. The xPDF conceals the details of the access network from the AF such that the solution for network construction can be simplified and the system maintenance may become simple and convenient.