Chinese ancestry, not Lao.
Thaksin Shinawatra - Wikipedia, the free encyclopedia
"[edit] Family background
Thaksin's great-grandfather Seng Sae Khu (surname 丘))was a Hakka Chinese immigrant from Meizhou, Guangdong who arrived in Siam in the 1860s and settled in Chiang Mai in 1908. His eldest son, Chiang Sae Khu, was born in Chanthaburi in 1890 and married a Thai woman, called Saeng Somna. Chiang's eldest son, Sak, adopted the Thai surname Shinawatra ("does good routinely") in 1938 because of the country's anti-Chinese movement and the rest of the family also adopted it.
Thaksin's father, Lert, was born in Chiang Mai in 1919 and married Yindi Ramingwong. In 1968, Lert Shinawatra entered politics and became an MP for Chiang Mai and deputy leader of the now-defunct Liberal party. Lert Shinawatra quit politics in 1976.
Thaksin's great-grandfather Seng Sae Khu made his fortune through tax farming. The Khu/Shinawatra later founded Shinawatra Silks and then by moving into finance, construction and property development. Lert Shinawatra opened a coffee shop, grew oranges and flowers in Chiang Mai's San Kamphaeng district, and opened two movie theatres, a gas station, and a car and motorcycle dealership. By the time Thaksin was born, the Shinawatra family was one of the richest and most influential families in Chiang Mai."