In this paper, Te-free Ga-Sb-Se material is considered to be a storage medium for phase change memory. Compared with Ge2Sb2Te5, Ga1Sb6Se3 exhibits a better thermal stability, which leads to a brilliant performance for data retention. Ga1Sb6Se3-based phase change memory cell shows reversible switching between reset and set states with a resistance ratio of two orders of magnitude. The minimum reset/set voltages are significantly lower than those of Ge2Sb2Te5-based one. Meanwhile, Ga1Sb6Se3 film possesses a faster switching speed than Ge2Sb2Te5. Thermal simulation confirms the improvement of cell performance originating from the low thermal conductivity and low melting point of Ga1Sb6Se3.