Abstract: A method of processing an open asynchronous application service event and an open web service gateway implementing the method are provided. The open web service gateway includes: a plurality of SCFs (service capability features) operatively connected to an application service through a web service interface, receives an event registration request from the application service, and notifies an event occurring in a network to the application service; and an event broker registering the registration-requested based on a predetermined policy in correspondence with the SCFs, when the registration-requested event received from the application service is an asynchronous event, and notifies an occurrence of the event in the network to the SCFs according to a registered priority of the event.