There are different opinions about the origin of China's traditional operas, such as primitive sacrificial songs and dances, court farce advocating Excellence since the Zhou Dynasty (everyone may have heard of the story of dreamy clothes), and narrative literature rap art appearing in the Tang Dynasty and so on. However, a more reasonable explanation is that China traditional drama is a mixture of all these art forms.
The truly mature form of traditional Chinese opera was in the Song Dynasty.
In northern China, due to the development of economy, a performance place like Goulan Washe appeared, and a mature drama form was formed in this promotion, which was called Song Zaju.
At the same time, in the south, the local folk songs and the tunes of Song people were used to sing stories, thus forming a form of China traditional opera. It's called Nanxi, also called Nanqu or Opera.
In the later development, these two forms of drama continued to blend and develop, and finally formed the drama we see now.
(The above summary is declined to be reproduced with reference to the course of China Opera History. )