Religion in Thailand is varied. There is no official state religion in the Thai constitution, which guarantees religious freedom for all Thai citizens, though the king is required by law to be Theravada Buddhist. The main religion practiced in Thailand is Buddhism, but there is a strong undercurrent of Hinduism with its distinct priestly class. The large Thai Chinese population also practices Chinese folk religions, including Taoism. The Yiguandao (Thai: Anuttharatham) spread in Thailand in the 1970s and it has grown so much in recent decades to come into conflict with Buddhism; it is reported that each year 200,000 Thais convert to the religion. Many other people, especially among the Isan ethnic group, practice Tai folk religions. A significant Muslim population, mostly constituted by Thai Malays, is present especially in the southern regions.
Religion in Thailand (Pew 2010)
According to the latest (year 2000) official religious demographics figures, 93% of Thais are Buddhists of the Theravada tradition.
However, the religious picture of the country is more complex. Of the large Thai Chinese population, most of those who follow Buddhism have been integrated into the dominant Theravada tradition, with only a negligible minority having retained Chinese Buddhism. Many other Thai Chinese have retained the practice of the Chinese traditional religion, including Taoism and other Chinese religions, but despite being practiced freely, these religions have no official recognition, and their followers are counted as Theravada Buddhists in demographic figures. Also, many Thais and Isan practice their own Tai folk religion.