The objectives of this research were to investigate general socio-cultural structures of the Tai Lue and to study the process, tendency, and factors influencing changes in the ethnic group in terms of language, dress and beliefs. It is found that the Lue originated from the Sipsongpanna Region, Sothern China. The ethnic group residing in northern Thailand was prisoners of war which were due to political changes in China. Their cultural practices and ethnic identity are still maintained. However, the investigation reveals that certain aspects of the tradition and culture of the Lue residents at Thung Mork Village have been changed, due to the improvement of infrastructure, communication, intermarriage, and trade. The cultural aspect that has changed the most is traditional dress, while language is least changed. Some beliefs have been maintained whereas others have been changed. Residents with higher education, of younger age, and higher social status are likely to accept new things and change more easily.