A photo taken on June 30, 2016 shows China's earliest imperial jade seal, which has been found in Northwest China's Shaanxi province. [Photo/Xinhua]

China's earliest imperial jade seal has been found in Northwest China's Shaanxi province.

According to preliminary analysis, experts believe the seal with a dragon figure on the top was the official seal of a tribal leader in the early period of the Western Zhou Dynasty (c 11th century-771 BC).

Experts further explain that the seal contains four graphic characters divided by a cross grid, which may refer to "dragon", "deer", "tiger" and "eagle". And a Bronze gui has also been excavated from the tomb of from the Western Zhou dynasty along with the seal.