The ceremony is being conducted at the compound of Buddhism's holiest shrine, the Mahabodhi Temple, under the ancient Peepal tree where the Buddha attained enlightenment.
The annual ceremony was inaugurated in 2006 on the occasion of the 2550th birth anniversary of Lord Buddha.
"Today is an important day for Buddhists as Tipitaka prayers have started. The prayers will go on for the next 10 days. Devotees, monks and tourists from 13 countries are participating in this event. A huge number of tourists have also flocked here," said district magistrate Sanjay Kumar Agarwal.
Bihar Chief Minister Jitan Ram Manjhi, who could not attend the event, extended his best wishes.
In the year 2002, the UNESCO declared Mahabodhi Temple as a World Heritage Site.