Song Zhaosu had started his political career as the head of the Organization Department of Zhoukou District Committee in Zhoukou, Henan province. Later on, he served as deputy secretary of the Shangshui County Committee and then was its magistrate and secretary of Taikang County. Following that he became a secretary of both Zhoukou and Xuchang districts as well as of Standing Committee of the National People's Congress and Political and Legal Committee of the Henan Provincial Party Committee.