The Shang Siyang Bronze Square Zun is a bronze ritual vessel and sacrificial item from the late Shang Dynasty. Unearthed in 1938 on the mountainside of Zhuanerlun, Yueshanpu, Huangcai Town, Ningxiang County, Hunan Province (Tanheli Site), it is now collected in the National Museum of China. The Shang Siyang Bronze Square Zun is the largest existing bronze square Zun from the Shang Dynasty in China, with a side length of 52.4 centimeters, a height of 58.3 centimeters, and a weight of 34.5 kilograms. The entire object of the Shang Siyang Bronze Square Zun was cast using block casting method, which was seamless and exquisite, demonstrating superb casting skills. It is known as the "ultimate bronze model" in the field of history and is listed as one of the top ten national treasures passed down in China.