An apparatus for quantum cryptographic communication includes a light source configured to generate an optical pulse which is transmitted to a plurality of quantum code sending devices, and a quantum entanglement measuring unit configured to receive the optical signal generated from each of the plurality of quantum code sending devices and measure a relation among quantum states of the optical signals received from the plurality of quantum code sending devices; the optical signal being generated by encoding a key to a quantum state of the optical pulse. The apparatus for quantum cryptographic communication may further include a signal direction determining unit, a reflector for reflecting the optical pulse or the optical signal, an arbitrary phase shifter, or a modulator for encoding a digital signal corresponding to the key to the optical pulse.