The objectives of this research are to compare tonal realizations in Yong in citation form and connected speech and between 2 age-groups as well as to prove whether there is tone sandhi in Yong as proposed by Ruengdet Pankhuenkhat (1978). Six female... that the Lamphun variety of Northern Thai is exerting influence on Lamphun Yong. Tone sandhi in two syllabic words is found only when the second syllable is tone 2 and the first is tone 3. Tonal variation found in this research shows that Lamphun Yong is different