Abstract: So far, the research about the origin of Thai family in Laos is mainly concentrated in Yue and Luo yue, however the researchers have almost no special discussion on the history relationship of the Thai family in today Laos and the Lao people in the next historical stage which originates from Yue.Historical records of China, Vietnam and folk legends in Laos show that from the Eastern Han Dynasty to the Tang and Song Dynasties, the main ethnic groups in Laos should be Lao people.