The Shan-hai-king relates that in the midst of the Green Ocean there is the Tu So Mountain, on which grows an enormous peach-tree. Its girth measures 3,000 Li. Between its boughs to the north-east there is the so-called door of the ghosts, where the ten thousand ghosts pass in and out. On the tree there are two spirits, one called Shên Shu (神荼), the other Yü Lü (郁垒), who have the superintendence over all the ghosts. They bind the wicked ones, who have wrought evil, with reeds, and feed the tigers with them.

Subsequently Huang Ti worshipped for the purpose of expelling the ghosts for ever. He erected a huge human figure of peach-wood and painted Shên Shu and Yü Lü along with tigers and cords of reeds hanging down on the house-doors, and thus frightened them away.

According to the Fêg-su-t'ung of the 2nd cent. a.d. this story is narrated in the Huang Ti shu, the Book of Huang Ti. On New-year's Eve the pictures of Shên Shu and Yü Lü are still at present pasted on the doorways as a talisman against evil spirits.

Some say Shên Shu is Golden Rooster, who lives on that enormous Peach-tree, and crows at dawn, all roosters in the world crow after them. Then the Golden Rooster fly down to feed on the ghosts. That's why ghosts are frighten away by them.

Some say Yü Lü are two tigers, named Yü and Lü respectively, they live under the Peach-tree. But others contend that Yü and Lü are two gods, who catch ghosts with reed cord, and feed the tigers. The widely accepted opinion is that Shên shu and Yü Lü are two gods, together with the Golden Rooster and the Tiger, they all live on or under the Peach tree.