In terms of politics, he governed the country with benevolence and righteousness, treated virtuous officials with courtesy, did not abuse punishment, and made clear rewards and punishments. Encourage ministers to make criticisms and suggestions on government affairs and be good at accepting advice. In order to reduce the burden on the people, he canceled all additional levies except rent and taxes. Precisely because of these measures, Emperor Xuanzong of the Tang Dynasty enjoyed political clarity and prosperity in his early years. During the Tang Dynasty, the Tang government engaged in very frequent foreign trade. At that time, it had contacts with more than 70 countries. The Tang government encouraged merchants from all over the world to trade with China and did not allow officials to increase taxes. Emperor Xuanzong of the Tang Dynasty valued culture and science and technology, so during his reign, there were many talents and bright stars. Various poems are rich in content and diverse in style. The political clarity led to the rapid development of economy and culture, which led to the prosperity of the world and an unprecedented prosperity during the Kaiyuan period. In the later period of Tang Xuanzong's reign, he gradually became greedy for pleasure, doted on Concubine Yang, and ignored political affairs. He also appointed treacherous ministers, causing chaos in the government and leading to a rebellion led by border generals An Lushan and Shi Siming. Historically, this rebellion was called " An Shi Rebellion". The Tang Dynasty gradually declined from then on.