Abstract: Kingdom of Nanzhao (738— 902) has two kinds of earthquake myths. One is that a huge Ao ( legendary green sea-turtle) always topples the mountains and overturns the seas in Erhai Lake, and causes the people and animals devastated by the earthquake. Even though he blinks when wakes up, the earth will shake. So that there is an earthquake by every more than 70 years, and a big earthquake by every 400 years. Therefore people set up a seismic monument at Wanghaitai to warn the later generations of the earthquake damage. The other is that the River God of Erhai lake, Duan Chicheng, can predict earthquakes and keep people safe. Once Duan Chicheng predicts there will be a big earthquake at midnight, he cooperates with two Mountain Gods and East River Fisherman. Mountain Gods change themselves to a chicken and a dog, then crow loudly and jump hardly before the earthquake to warn people. East River Fisherman reports to the eastern villagers. River God of Erhai lake changes himself to an old man and reports to the western villagers. 90% villagers believe in them and leave houses to the flat ground, so people and domestic animals are safe. But the others not to believe in them suffers a lot damages.