People's moral behavior in Yao, Shun and Yu period was natural and universal, but their moral level was higher than that in the early Zhou Dynasty when the door was closed at night and gold was left on the road. Although the legendary dragon, phoenix and unicorn appeared in the sacred world, people in that period could often see them. It is said that dragons represent wisdom and belong to gods; Phoenix represents civilization and belongs to literary talent; Kirin represents moral behavior and belongs to kindness and auspiciousness. Whenever saints come to rule the world, there will be auspicious animals. When the Yellow Emperor came out of the water, there was a record of a phoenix falling in Qishan. Legend has it that Kirin is kind. In order to avoid unintentional injury to insects and ants, it pays great attention to the life of its feet whenever it walks, and its feet never land easily. So there is a wonderful legend of "deep step in spring".