This is the only empress’s jade seal of the Han Dynasty discovered so far, which embodies the dignity and authority of the empress in the imperial court of 2,000 years ago. It is roughly square-shaped with a carved Chihu tiger as the gripper top, representing the ruler’s power over the world and the absolute authority above the officials. The material is yangzhiyu jade (literally meaning “mutton-fat jade”) from Hetian region of present Xinjiang, which is well-known for its warmth, pure white color and creamy glossiness, making it highly ornamental. The four characters on the bottom meaning “Empress’s Seal” were engraved smooth and elegant in a traditional calligraphic style, demonstrating the excellent techniques of the artisans of the time. Because the seal was found only one kilometer east to the joint mausoleum of Emperor Gaozu of Han and his empress Lyu Zhi, it is speculated to have been used by Empress Lyu. As a national treasure, it is of great significance for studying the imperial seal system of Qin and Han dynasties.