The research investigated patterns, belief symbols, and the role of the Sa Erng Dance ritual of the Kui ethnic group at Kra Saeng Yai Village, Tambon Kra Saeng, Kanthoralak District, Sri Saket Province. Participatory observations and interviews of key informants were used to collect the data for this qualitative study. It was found that the cosmology of the ethnic group was based on a mixture of Hinduism, Buddhism and animism. Belief in ancestors’ spirits was the basis to perform this ritual dance and the cultural meaning of the dance was a culturally related process in the context of the ethnic group. The ritual dance was performed by a medium while being possessed by the Sa Erng Spirit in order to heal sicknesses that could not be treated by modern medicine. When the illness was healed, the dance was performed as a gesture of thanks to the spirit. There were three main purposes of the dance to the Kui community, including socialization, social unity, and morale boosting.