1. A presence system, comprising: at least one client that includes a plurality of presentity agent means for providing presence information indicating at least the state of own entity; a plurality of subscriber means for receiving said presence information; and a server that includes a presence service means for delivering said presence information received from said presentity agent means to said plurality of subscriber means; wherein said plurality of presentity agent means are provided with a notification means for notifying said presence information to a specific subscriber means only, wherein said plurality of presentity agent means include a means for automatically deriving a list of said specific subscriber means in accordance with a notification destination determination rule held by said plurality of presentity agent means, wherein said notification means notifies said presence information to said specific subscriber means derived only, wherein said subscriber means determines subscriber means to which said presence information is to be notified in accordance with the order in which said subscriber means have performed subscription.