New Book of Tang
Little is known about Su Jian's family background, as he did not have a biography in either of the official histories of Tang Dynasty, the "Old Book of Tang" and the "New Book of Tang", and it is not known when or where he was born. According to the table of the chancellors' family trees in the "New Book of Tang", Su's family was described as "from Wugong". His grandfather was named Su Tiao (蘇迢), and his father was named Su Meng (蘇蒙); neither was listed with any official titles.