The Lue migrated from Sipsongpanna to northern Thailand and were culturally assimilated with the Yuan, the majority group in the region. Therefore, the issue, "Who are the Lue?", is an ambiguous issue. This research examined the current situations of the Lue identity in northern Thailand, especially three Lue villages in Tha Wang Pha district, Nan province. The three villages (N, D and T) maintained their ethnic identity by conducting an appeasement ritual for Chao Luang Muang La, which was connected to their memories about their migration from Sipsongpanna and other migration legends. An important issue in the ritual is the memory about the pantheon of Chao Luang Muang La and important positions of ritual participants. Hierarchy of the City Spirits indicates the legend of Tai Lue army during their migration, while Chao Muang and Mor Muang indicate the lineal relationship with Sipsongpanna. When ritual development projects and the local administrative system of the state have come into the villages, there have been attempts to express the ethnic identy by redefining the ritual in connection with the histories and memories of each village.