A ground rod and connection sleeve comprising: an overhead earth wire that is installed to protect a transformer and power-transmission lines from the lightning; a ground wire that is extended from a lightning arrester to ground; a multi-stage ground rod that is elongated by a thread type connection under the condition that it is connected with the end of the ground wire and that it is buried into the ground; and a connecting sleeve for connecting the ground rod to the ground wire, wherein the ground rod comprises a basic part forming a conical tip for penetrating into the ground in one end of the rod, and a threaded rod in the other end of the rod; a multitude of connecting rods forming a nut hole corresponding to the threaded rod of the basic part for being connected with ^ basic part in the one end of the rod, a threaded rod which is of same size in the other end; a lead terminal forming a nut hole in the one end of the rod, and a lead wire inserted in the other end, characterised in that the connection sleeve is filled with an electrically conductive compound; wherein the electrically conductive compound for preventing corrosion is provided in the thread connection, a junction of the lead terminal side of the connecting sleeve and a junction of the ground wire side of the connecting sleeve, wherein the electrically conductive compound in a gel-state is provided in the nut holes (221, 231), respectively; and wherein the electrically conductive compound is composed of a grease of 33 to 37% by weight, silicon carbide particles of 62 to 66% by weight, and sodium and calcium of 1 % by weight and Wherein the dropping point of the electric conductive component is equal to or greater than 120°C and it does not flow at or below 100°C. an overhead earth wire that is installed to protect a transformer and power-transmission lines from the lightning; a ground wire that is extended from a lightning arrester to ground; a multi-stage ground rod that is elongated by a thread type connection under the condition that it is connected with the end of the ground wire and that it is buried into the ground; and a connecting sleeve for connecting the ground rod to the ground wire, wherein the ground rod comprises a basic part forming a conical tip for penetrating into the ground in one end of the rod, and a threaded rod in the other end of the rod; a multitude of connecting rods forming a nut hole corresponding to the threaded rod of the basic part for being connected with ^ basic part in the one end of the rod, a threaded rod which is of same size in the other end; a lead terminal forming a nut hole in the one end of the rod, and a lead wire inserted in the other end, characterised in that the connection sleeve is filled with an electrically conductive compound; wherein the electrically conductive compound for preventing corrosion is provided in the thread connection, a junction of the lead terminal side of the connecting sleeve and a junction of the ground wire side of the connecting sleeve, wherein the electrically conductive compound in a gel-state is provided in the nut holes (221, 231), respectively; and wherein the electrically conductive compound is composed of a grease of 33 to 37% by weight, silicon carbide particles of 62 to 66% by weight, and sodium and calcium of 1 % by weight and Wherein the dropping point of the electric conductive component is equal to or greater than 120°C and it does not flow at or below 100°C.