A history management system of an electronic locking device comprising a cylinder plug which is located inside a cylinder housing forming an appearance, installed rotatably in place, locked or unlocked to a cylinder housing, and detached from a key head of an electronic key, wherein the cylinder plug includes: a data communication unit which is electrically contacted with a terminal unit provided in the key head of the electronic key; a data processing unit that determines authentication by comparing ID information of the electronic key transmitted by the data communication unit with a pre-stored ID database, and a lock head for detachably mounting the key head of the electronic locking device, for being formed a second supporter corresponding to a first supporter on the key head, and for fixing the electronic locking device by engaging the second supporter with the first supporter; characterized in that the second supporter includes: a head portion which is roundly formed on a peripheral surface of a key insertion hole and is exposed to the outside from the circumferential surface of the key insertion hole, a guide shaft which is integrally extended from the head portion, and an elastic body which is coupled to an outer circumferential side of the guide shaft, wherein the first supporter is formed on an outer circumferential surface of the key head as a concavely recessed groove, and the second supporter is provided on a circumferential surface of the key insertion hole to which the key head is inserted, corresponds to the first supporter, and is formed as an elastically supported protrusion, and wherein when the key head is inserted to the key insertion hole, the head portion of the second supporter is pressed and jumped out by the elastic restoring force of the elastic body to press and support the first supporter of the key head. wherein the cylinder plug includes: a data communication unit which is electrically contacted with a terminal unit provided in the key head of the electronic key; a data processing unit that determines authentication by comparing ID information of the electronic key transmitted by the data communication unit with a pre-stored ID database, and a lock head for detachably mounting the key head of the electronic locking device, for being formed a second supporter corresponding to a first supporter on the key head, and for fixing the electronic locking device by engaging the second supporter with the first supporter; a data communication unit which is electrically contacted with a terminal unit provided in the key head of the electronic key; a data processing unit that determines authentication by comparing ID information of the electronic key transmitted by the data communication unit with a pre-stored ID database, and a lock head for detachably mounting the key head of the electronic locking device, for being formed a second supporter corresponding to a first supporter on the key head, and for fixing the electronic locking device by engaging the second supporter with the first supporter; characterized in that the second supporter includes: a head portion which is roundly formed on a peripheral surface of a key insertion hole and is exposed to the outside from the circumferential surface of the key insertion hole, a guide shaft which is integrally extended from the head portion, and an elastic body which is coupled to an outer circumferential side of the guide shaft, wherein the first supporter is formed on an outer circumferential surface of the key head as a concavely recessed groove, and the second supporter is provided on a circumferential surface of the key insertion hole to which the key head is inserted, corresponds to the first supporter, and is formed as an elastically supported protrusion, and wherein when the key head is inserted to the key insertion hole, the head portion of the second supporter is pressed and jumped out by the elastic restoring force of the elastic body to press and support the first supporter of the key head. a head portion which is roundly formed on a peripheral surface of a key insertion hole and is exposed to the outside from the circumferential surface of the key insertion hole, a guide shaft which is integrally extended from the head portion, and an elastic body which is coupled to an outer circumferential side of the guide shaft, wherein the first supporter is formed on an outer circumferential surface of the key head as a concavely recessed groove, and the second supporter is provided on a circumferential surface of the key insertion hole to which the key head is inserted, corresponds to the first supporter, and is formed as an elastically supported protrusion, and wherein when the key head is inserted to the key insertion hole, the head portion of the second supporter is pressed and jumped out by the elastic restoring force of the elastic body to press and support the first supporter of the key head.