Ubasi Khong Tayiji was a 17th-century Mongolian prince. He was the first Altan Khan of Khalkha who ruled Khotgoids in northwestern Khalkha See Altan Khan of the Khotgoid. About 1609 he occupied the former Oirat heartland around Kobdo and Lake Ubsa Nor. He drove the Oirats west into Dzungaria in 1620 and 1623. Ubasi was killed by the Oirats in 1623 and was succeeded by his son Badma Erdeni Khong Tayiji.