A cartridge disposed on each of the floors of a drug dispensing apparatus and connected to each of a plurality of drug dispensing boxes, the cartridge comprises: a cartridge housing comprising a lower housing supporting the drug dispensing box and a rear housing restricting entry of the drug dispensing box by a predetermined distance; a rail disposed along an entry path of the drug dispensing box on the lower housing; and a first data transmitting/receiving terminal connected to the drug dispensing box to transmit/receive data, wherein the drug dispensing box comprising, a dispensing box housing, a rail accommodation unit defined in a bottom surface of the dispensing box housing to guide the dispensing box housing along an entry path of the cartridge when the rail of the cartridge is accommodated for the dispensing box housing to be connected to the cartridge, a data terminal unit electrically connected to the cartridge to transmit/receive data into/from the cartridge, at least one gear receiving external power, and a power transmission blocking unit restricting rotation of the gear or releasing the gear depending on a position of the rail, wherein the power transmission blocking unit releases the gear when the rail of the cartridge is accommodated to the rail accommodation unit of the drug dispensing box, wherein the power transmission blocking unit comprises: a rotation part comprising a first end alternately rotating in a direction of the gear and in a direction opposite to that of the gear with respect to a rotation shaft and a second end disposed on the other side of the first end to rotate in a direction opposite to the rotation direction of the first end; and a blocking unit body connected to the second end, the blocking unit body comprising a second protrusion inserted between teeth of the gear, wherein the blocking unit body is retreated together with the second end when the second end rotates in a direction opposite to that of the gear to allow the second protrusion to be separated from a space between the teeth of the gear. a cartridge housing comprising a lower housing supporting the drug dispensing box and a rear housing restricting entry of the drug dispensing box by a predetermined distance; a rail disposed along an entry path of the drug dispensing box on the lower housing; and a first data transmitting/receiving terminal connected to the drug dispensing box to transmit/receive data, wherein the drug dispensing box comprising, a dispensing box housing, a rail accommodation unit defined in a bottom surface of the dispensing box housing to guide the dispensing box housing along an entry path of the cartridge when the rail of the cartridge is accommodated for the dispensing box housing to be connected to the cartridge, a data terminal unit electrically connected to the cartridge to transmit/receive data into/from the cartridge, at least one gear receiving external power, and a power transmission blocking unit restricting rotation of the gear or releasing the gear depending on a position of the rail, wherein the power transmission blocking unit releases the gear when the rail of the cartridge is accommodated to the rail accommodation unit of the drug dispensing box, wherein the power transmission blocking unit comprises: a rotation part comprising a first end alternately rotating in a direction of the gear and in a direction opposite to that of the gear with respect to a rotation shaft and a second end disposed on the other side of the first end to rotate in a direction opposite to the rotation direction of the first end; and a blocking unit body connected to the second end, the blocking unit body comprising a second protrusion inserted between teeth of the gear, wherein the blocking unit body is retreated together with the second end when the second end rotates in a direction opposite to that of the gear to allow the second protrusion to be separated from a space between the teeth of the gear. a rotation part comprising a first end alternately rotating in a direction of the gear and in a direction opposite to that of the gear with respect to a rotation shaft and a second end disposed on the other side of the first end to rotate in a direction opposite to the rotation direction of the first end; and a blocking unit body connected to the second end, the blocking unit body comprising a second protrusion inserted between teeth of the gear, wherein the blocking unit body is retreated together with the second end when the second end rotates in a direction opposite to that of the gear to allow the second protrusion to be separated from a space between the teeth of the gear.