2. Ethnic reasons: all ethnic groups in China tend to merge from struggle;
3. Cultural reasons: international cultural exchanges are increasingly frequent;
4. Ideological reasons: all kinds of ideas are compatible with the Tang Dynasty, and Confucianism, Taoism and Buddhism coexist;
5. Institutional reasons: The imperial examination system broke the monopoly of nobles on opinions, and the Jinshi examination in the imperial examination was mainly poetry and fu.
And the strong advocacy of the rulers.