A forensic scientist of the Southern Song Dynasty. His courtesy name was Huifu, and he was from Jianyang (now part of Fujian). From a young age, he was diligent in his studies and never tired of learning. After entering the Imperial Academy, he became a student of the Neo-Confucianist Zhen Dexiu. In the tenth year of the Jiading era (1217), he passed the imperial examination. He served as the magistrate of Changting County and the military governor of Shaowu in Fujian, where he did much beneficial work for the people.

In the third year of the Jiading era (1239), Song Ci was promoted to the position of Judicial Commissioner of Guangdong. In the fourth year of Jiading, he was transferred to the position of Judicial Commissioner of Jiangxi and concurrently served as the prefect of Ganzhou. In the first year of the Chunyou era (1241), he was appointed as the military governor of Changzhou. In the fifth year of Chunyou (1245), he began collecting and compiling materials for Xiyuan Jilu. In the seventh year of Chunyou (1247), Song Ci was appointed as a direct secretary of the Imperial Library, Judicial Commissioner of Hunan, and concurrently served as a counselor in the military governor's office, assisting in handling important military and administrative affairs.

In his long career as a Judicial Commissioner, Song Ci believed that forensic examination was a matter of great importance, relating to the life and death, justice and injustice of the entire case (Xiyuan Jilu‧Preface by Song Ci). Therefore, he always approached each case with utmost care, "examining it repeatedly, not daring to harbor the slightest negligence." Through careful and prudent practice, Song Ci summarized an important lesson: wrongful convictions and miscarriages of justice were closely related to insufficient forensic experience. Thus, he extensively collected various books from recent times, including Neishu Lu and several others, compiling and refining them, adding his own insights, and consolidating them into a single volume, titled Xiyuan Jilu. It was published in Hunan for the reference of forensic officials within the province, aiming to achieve the goal of "clearing wrongs and benefiting the people." This renowned forensic work quickly spread throughout the country and became the foundational text for many forensic books in later generations. After Song Ci's death, Emperor Lizong, in recognition of his contributions, personally inscribed the epitaph for his tomb.