The present invention relates to a cartridge for a drug packaging apparatus, which is provided to easily rotate a rotor and insert tablets into a tablet insertion groove formed at the rotor since the cartridge reduces load applied to the rotor. The cartridge comprises the rotor which has the tablet insertion grooves between guide teeth, wherein a plurality of guide teeth protrudes at regular intervals along the outer circumference of the rotor; a case which has a storage room receiving tablets therein, a rotor mounting unit which is formed on the lower part of the storage room to place the rotor, and a discharge hole which is formed at the lower part of the rotor mounting unit to correspond to the tablet insertion groove; a tablet sensing unit which is installed inside the case and senses whether the tablets are in the case or not; and an output unit which is installed outside the case, is connected to the tablet sensing unit and displays whether the tablets detected by the tablet sensing unit.