Although the cultural assimilation of the Lao Khrang ethnic group took place under changed social conditions, in reality the assimilation process took place under socio-political conditions and these conditions were crucial to the process. Local ethnic history and contemporary events show that the trade-oriented economic system since King Rama III, municipality political reforms, a political change to democracy, and national developments since 1961 have been the major factors in the cultural assimilation of Lao Khrang into the mainstream. Other factors included state propaganda: state regulations and laws concerning family names, conscription, household registration and the abolition of traditional customs; and a western-oriented lifestyle during P.Phibulsongkhram’s government. It was inevitable for the ethnic group to avoid the cultural assimilation process. After these mechanisms were applied throughout the country, it was inevitable that assimilation was according to the same pattern. The question is what would happen when every ethnic group was assimilated in the same direction despite the fact that minority ethnic groups like the Lao Khrang did not have equal opportunities and potential to adjust themselves to the mainstream cultural environment.