Provided are a titanium-based amorphous alloy and a phase-change memory device in which the titanium-based amorphous alloy is applied to a phase-change layer. The titanium-based amorphous alloy may include titanium, antimony, and at least one metallic component. The titanium-based amorphous alloy may be configured as a phase-change material having a reversible phase change between a titanium-based amorphous alloy phase and at least one crystalline phase.