The day before an annual lamp festival, the Taer Monastery in northwest China's Qinghai Province was already full of pious believers and tourists eager to catch a glimpse of a dance ritual at one of the biggest events for Tibetans.

The Butter Lamp Festival celebrates the beginning of a new year on the Tibetan calendar and is an occasion to pray for happiness and good health by lighting butter lamps. This year's festival falls on Friday, the same day as the traditional Lantern Festival.

"I came here to watch the Cham dance," said Tsokyi, a believer from Qinghai's Yushu Tibetan Autonomous Prefecture. "I heard that the ritual can exorcise demons, and I pray for health and safety for my family."

At 1 p.m., the Cham dance began in a square in the monastery. The lead dancer, donning an animal mask and a skull crown, played the role of a king, while a dancer with a long beard was in charge of the ritual. A long-haired "ghost" wore a mask with wide-open eyes. The colored masks worn by the dancers bore varied expressions -- amiable, ferocious or fearful.

In the middle of the ritual, a motley crew of smiling little buddhas played by children stepped on the scene.

Tsomo, a monk at the monastery, said that the Cham dance is more than 280 years old.

"It's an important religious ritual performed to expel evil spirits," Tsomo explained.

The performers -- equipped with masks, musical instruments and colorful robes -- play the roles of ghosts, gods and goddesses, Tsomo said.

"They express the teachings and philosophy of Tibetan Buddhism by dancing to mysterious tunes," he said.

When a dancer with an ox mask showed up, pious believers started to kneel and bow, while onlookers presented the hada, a traditional Tibetan scarf, as a way of alms giving.

"Even though I do not quite understand the performance, it is quite theatrical," said a tourist surnamed Zhang, from neighboring Gansu Province. "I believe that if you are sincere, your prayers will be heard and answered, and I pray for a year of happiness and health."

For a long time, the charm of the Cham dance has attracted many visitors. For many Buddhists, the Cham dance can help deepen their beliefs and spread Buddhist teachings.

"It's simply amazing," said a tourist from Taiwan.

Tashi Drolma, a Tibetan, said that she comes to watch the Cham dance ritual almost every year.

"It's more than a religious ritual to me," she said. "It's where we say prayers and welcome a new year."

The Butter Lamp Festival is expected to draw more than 100,000 tourists to the monastery this year. The monastery has more than 100,000 cultural heritage items.