Nitrogen-doped Ge2Sb2Te5 (N-GST) film for phase change memory was prepared by reactive sputtering. Testing results show that doped nitrogen combines with Ge to form GeN, which not only restrains crystal grain growth but also increases the crystallization temperature and phase transformation temperature of Ge2Sb2Te5 (GST). Phase change memory (PCM) with N-GST can realize three-state storage in one PCM cell by using the resistivity difference between the amorphous state, the face centered cubic phase and the hexagonal phase of GST.