A device management system and device management scheduling method thereof, in which a server transmits to a client a scheduling context including a device management command and a schedule for the performing of the device management command, and the client generates a device management tree using the device management scheduling context, performs the command when a specific scheduling condition is satisfied, and, if necessary, reports the command performance result to the server, whereby the server performs a device management such as requesting a command to be performed under a specific condition, dynamically varying the scheduling condition, and the like.