The objectives of this research are threefold.  Firstly, to study the history and the significance of  Mekong Basin Community  and Phra That Phanom.  Secondly, to study the beliefs and the rituals of Mekong Basin Community  which  related to Buddhism and Phra That Phanom.  Thirdly, to study the influence of  Phra That Phanom  in  the beliefs and  the rituals of  Mekong Basin Community.

                     From the research, it is found that the Mekong Basin Community consists of  races, minorities, ethnic groups as well as numerous native languages.  Though they were primitive, underdeveloped and poorly agricultural societies, they consistently, strongly and periodically maintained and performed their customs, traditions, belief and ritual activities. The Buddhist Dharmas were introduced  into this area during the regime of King Asoka the Great after the Buddha’ lifetime. Phra That Phanom is the cetiya or stupa containing the Buddha’ rip relic which was firstly built in B.E. 8, and was reconstructed in B.E. 2522  after being collapsed in B.E. 2518. Phra That Phanom plays significant roles as follows : (1)  The Buddhist stupa and Buddhist artwork,  (2) the symbol of political power and administrative authority, (3) the centre of community, the junction of commercial trade, the cross-road of communication, travelling and tourism, and  (4) the centre of the miraculous power, the faith, the belief and ritual activities.

                     Regarding the beliefs and the rituals of Mekong Basin Community which related to Buddhism and Phra That Phanom, the results of the study indicate that these virtues were transformed and expressed in the form of twelve monthly traditional rituals which are called Heed-Sip-Song Festival. They are : Khao Karma, Koon Larn, Khao Jii, Pha Ves, Song Kran, Bang Fai, Zam Ha, Khao Pan Sa, Khao Pra Dap Din, Khao Saak, Aok Pan Sa and Ka Thina Festival. These celebrations are mainly the Buddhist ceremonies, and are of the awareness of supernatural powers such as ghost and Naga is also inherently concerned.

                     The study of the influence of  Phra That Phanom can be concluded as follows : 

(1) Phra That Phanom has the influence in the beliefs of miraculous powers because of  being the stupa containing the Buddha’s relic, the legend of  Uranga, the records of the past and the present experience,  (2)  Phra That Phanom has the influence in the beliefs of ghosts, through the legend that the Indra had obliged a group of three fierce guardian spirits to protect Phra That Phanom,  (3) Phra That Phanom has the influence in the beliefs of  Naga and Naga’s fireballs, from the phenomena that there were seven Nagas from Anodaad Reservoir, Himalayan Ranges, all of which were assigned by the Indra to protect Phra That Phanom,  (4) Phra That Phanom has the influence in the beliefs of  Karma, Merit, Evil, Hell and Heaven,  and  (5) Phra That Phanom has the influence in the beliefs of  one’s specifical significance such as the beliefs in Kha O Kaad (Phra That Phanom’s slavery), Look Phra That (Phra That Phanom’s inheritor) and the graceful dance during the yearly worship festival of Phra That Phanom or the third month’s sacred ceremony.