The ceremony is a ritual to reject the reinforcements carried out by the Petalangan Tribe in Riau. This traditional ceremony is usually held at night in the homes of sick people or in large traditional houses so that it can accommodate the large number of people attending this ceremony.

In general, buying is intended to treat sick people, help pregnant people who are suspected of having difficulty giving birth, reject disease outbreaks, and treat wounds from wild animal attacks. Treatment is done by a kemantan (dukun) by singing a mantra to summon the spirits.

The term belian comes from the word bolian which means offering. Thus, a ceremony can be interpreted as a ceremony offering to God to be healed of disease and kept away from danger.

Traditional ceremonies consist of two types, namely buying small (small) or biaso (ordinary) and buying bose (large) or polas (special). Purchasing biaso is a ceremony held for pregnant people who are suspected of having difficulty giving birth, and for people affected by an outbreak of disease or getting a disturbance of wild animals. If the purchase ceremony is not able to cure the disease, then bose or polas are held.

This ceremony is held at night. Night is considered the right time to pray and beg God. In addition, at night all tribesmen can gather together because if they work in the forest during the daytime.

This ceremony is usually held at the home of a sick person. This ceremony can also be held in a large traditional house so that it can accommodate many people. Customary stakeholders assisted by residents will make small houses in front of the house which are used as ceremonies as one of the ceremonial requirements.

The ceremony is usually attended by families and sick relatives. This traditional ceremony itself is collective, involving the whole tribe.

Until now, the belian ceremony is still well maintained, one of them is in Betung Village, Pangkalan Kuras District, Pelalawan Regency, Riau. The village known as the Petalangan Cultural Center is a tourist village. There, visitors can witness the diverse cultures and indigenous arts of the Petalangan tribe.