1. In the early Tang Dynasty, during the Zhenguan period of Emperor Taizong, the country was stable, the economy was prosperous and the style of writing was fresh.
2. During the prosperous Tang Dynasty, during the Xuanzong, Kaiyuan and Yonghui periods of the Tang Dynasty, the country and culture reached their peak and their literary achievements were rich.
3. In the middle Tang Dynasty, after the Anshi Rebellion, the political situation of the imperial court was turbulent, and poetry tended to express the suffering of survival and the fate of the people.
4. In the late Tang Dynasty and the Five Dynasties, the demise of the Tang Dynasty approached, and poetry showed great emotional characteristics such as pain, seclusion and bitterness.