The embodiments of the present invention disclose a method and device for controlling media resources, and a method and system for establishing calls. The method for controlling media resources includes the steps of: indicating source attributes of at least one of locally transmitted media and locally received media to a first media gateway, which also includes: receiving source attributes of locally transmitted media reported from the first media gateway; when the source attributes of locally transmitted media and destination attributes of locally received media of the first media gateway are at least partly identical, determining the source attributes of locally transmitted media by receiving the destination attributes of locally received media reported from the first media gateway.