The Mongols have many traditional ceremonies in offering sacrifices, such as offering sacrifices to Heaven, to Fire, to Ancestors and to Aobao etc., among which offering sacrifices to Aobao is the most important one.

The word "Aobao" comes from the transliteration of Mongol, which is also called "Ebo", "Naobao" etc., and its meaning is "Heap". Originally, it indicated the heaps of stones or rideau on the boundary of nomadism or road, which served as a sign. As is recorded in Qing Hui Dian: on the boundary of the nomadism, if there is no hill or river which serves as the sign, a heap of stone will do that job, which is called Aobao". Afterwards, such heaps were considered as the residence of the gods, and an idol for people to worship and offer sacrifices to. Therefore, the terminus and road sign became the places to offer sacrifices to god of mountain, god of road and other gods who protected the villagers. Such places can even be built according to people's needs. In the ancient times, each Qi, Sumu and temple had its own public Aobao. Some rich families also built their own Aobaos, with each one had its own name.

Usually, the Aobaos are built high on the massifs. Most of them are piled up with stones and some are also enclosed and built with wickers and filled with sands and soils. The Aobao usually looks like a round bundle, and some also have domes and square bases. Several poles and branches are stuck into the Aobao, with all colors of flags and silk lists hanging on them. In the Aobao, there are corns, bows and arrows, or even figures of Buddha buried in the earth. The size and the amount of Aobao vary greatly. Most of them are alone, but there are also some groups, consisting of 7 or 13 Aobaos, and the main one in the center is larger than the others.

In the past, the ceremonies of offering sacrifices to Aobao were often held between May and July in the Chinese lunar calendar. In such season, the grass was lush and the herds were tallowy. At that time, the chief Sumu, the chief Qi and even the people from the nearby villages all brought along with the young and the old, with hada, mutton, fermented milk and other milk-made food and came to the Aobao. They first presented the hada and the offerings, and the Lama would read the Tripitaka and pray, and all the people worshiped on bended knees. Then, they would add some stones to the Aobao, or mend it with wickers, and put new sutra streamer and colorful silk lists on it. Finally, all the participants would go round the Aobao three loops clockwise, and pray to god to bless them, and make both themselves and their flocks and herds prosper. After the ceremony, there were usually some horse race, wrestling, archery and Bulu throwing and such traditional sports games.

In the early days, the Mongols believed in Shamanism, and in late Ming and early Qing, Buddhism came from Tibet and gradually took the place of Shamanism and was believed by the whole nationality. Therefore, Lama and reading Tripitaka played a leading role and became the most important content in the ceremonies of offering sacrifices to Aobao. Besides, the Buddhist service has also been spread all over and into every aspect of the Mongol's everyday life and production.