Se-doped GeSb were investigated for the possible applications in three-level phase-change memory. Ge15Sb85Se0.8, as a typical composition, has two abrupt drops of electrical resistance during an in situ temperature-dependent resistance measurement. The large-resistance change in the two drops and the stable middle-resistance state make Ge15Sb85Se0.8 a good candidate for the three-level data storage applications. Three-level phase-change memory based on Ge15Sb85Se0.8 has been fabricated and demonstrated. X-ray diffraction patterns indicate that the reason for the middle-resistance state in Ge15Sb85Se0.8 is due to the incomplete crystallization. (C) 2009 Elsevier Ltd. All rights reserved.