This article intends to analyze the relationship between Buddhism and the indigenous beliefs that are evident in the Tai myths of the Buddha’s relics. From the analysis of the characters and their symbolic behaviour, we can see that the religious beliefs of the Tai people were very complex. The relationship between religious beliefs shown in the myths of the Tai people shows various characteristics and can be categorized into three groups: first, the conflict between Buddhism and indigenous beliefs into Buddhism: and third, the integration of Buddhism into indigenous beliefs. The kind of relationship that occurs in each group is due to the variety of aspects of these beliefs that coexist. The conflict between Buddhism and indigenous beliefs is reflected in the myth’s plot, motif and character behaviour, which is due to the conflicting behaviour of the two completely opposite belief systems in the myths. The acceptance of each offer between the two belief systems is reflected in certain sets of motifs and character behaviour. The study of the integration of the two belief systems shows the development of the mythical characters and their behaviour, thus reflecting the religious thoughts and beliefs of the Tai people.