The Aobao Festival is a traditional worshipping festival of the Evenki people. It is held from April to June of each lunar year in the Evenki-inhabited area of the Inner Mongolia Autonomous Region.

"Aobao" means heaps of stones. Aobao worship involves praying for good weather and safety for both humans and livestock. The Aobao is mainly located on top of mountains, and is a pile of stones or clods, with colorful strips or paper hung on top.
According to legend, at a summer night, a woman came to a village in a sedan chair drawn by a mule. Wailing and screaming ceaselessly, she caused a storm that tortures the whole village. That winter, when people broke the frozen ice in the rivers to fetch water, they discovered a woman's head, which is believed to be an evil spirit. At that moment, wind began to howl and it suddenly started snowing. Everyone was petrified.

The villagers invited nine lamas who trapped the evil spirit and pressed her under the stones. Worrying that she would escape, the people added a stone to the pile whenever they passed so as to increase the pressure. However, they still did not feel assured. The villagers regularly begged the evil spirit not to cause anymore disasters; they asked her to bless them and their animals, and grant them prosperity. From April to June, many worshippers added stones to the pile. Eventually the practice became a tradition.

Rituals of the Aobao include clan worship, family worship, and village, county and league worship. There are different Aobao worship forms. For instance, the Aobao of a clan is held within by families, and the offerings and costs are shared among them. The Aobao of the league is worshipped within the scope of the league and the offerings and other associated costs are shared by people in the league. There are also volunteers who often make contributions. Well-off families often present several sheep at once. A person is appointed as herdsman of the livestock for next year's offerings.

During the festival, people from far and wide gather at the Aobao to take part in worship activities. After a horse race, offerings are made and the lamas pray. The participants start adding stones to the Aobao one after another. When it is finished, entertainment, such as wrestling, singing and dancing, is provided.

Nowadays, the Aobao Festival is considered more of a mass entertainment rather than religious ceremony, featuring sports activities and fairs that are similar to the Mongolian Nadam Fair.