In this study, we investigated the Al-Sn flux system and its growth conditions to obtain AlN single crystals. AlN single crystals of a size of 50m were successfully grown using an Al-Sn melt under nitrogen gas pressure. The growable region of the AlN crystals was established using a pressure-temperature diagram. The required nitrogen gas pressure for the growth of the AlN crystals was found to decrease with increasing temperature, and AlN was grown at 0.1MPa nitrogen pressure above 1300 degrees C. By investigating the AlN yield with various Al concentrations, we confirmed that the Al component in the Al-Sn melt facilitated nitrogen dissolution. Finally, scanning electron microscopy analysis showed that the obtained AlN particles showed good morphology.