Sb2Te3 alloy, as one of the representative phase change base materials, is largely limited by its low thermal stability in the practical application. Here, both tungsten and titanium are used to improve the thermal stability of materials. After co-doping, the crystallization temperature is significantly increased, and the increment will be leveled up if more tungsten content was doped in the W-Ti-(Sb2Te3). Specifically, the amorphous-to-metastable FCC phase transition temperature is about 120 degrees C for pure Sb2Te3, approximately 230 degrees C for W0.03Ti0.045-(Sb2Te3)(0.925), and around 304 degrees C for W0.07Ti0.045-(Sb2Te3)(0.885), respectively. Beyond that, the second FCC-to-hexagonal phase transition temperature is also improved due to the addition of tungsten atoms, as obtained from the XRD analysis result. As observed in the bright images of W0.03Ti0.045-(Sb2Te3)(0.925), tungsten dopant can refine the crystalline grains effectively further, by utilizing transmission electron microscope. In the final, electrical characterization of phase change memory devices proves W0.03Ti0.045-(Sb2Te3)(0.925) owns excellent operation properties, such as higher-speed reversible write/erase, and better resistance stability of both high and low states, compared with the widely used Ge2Sb2Te5 phase change material.