Provided are a system and method for interworking Service Capability Features (SCFs) and protocols in an open service gateway. The system includes service capability features that generate and process various protocol messages, and a protocol stack that enables an interwork with a communications network. The protocol stack includes: one or more units that maintain various protocols, a unit that performs data connection and transmits and processes messages, and a unit that manages the various protocols. In the protocol stack, protocol identifiers that differentiate the protocols from one another, and message identifiers that differentiate service capability features from one another are stored in the unit that manages the various protocols.