This paper will examine the writings that are commonly attributed to Huan Tan. According to the biography of Huan Tan in the History of the Later Han, his works include Xin Lun (A New Theory), totaling twenty-nine chapters, and other twenty-six writings. Since these works have been lost, presently we can only see the editions of writings searched and pieced together by his later generations. Among the academia today, many believe that Xin Lun has been lost in the Southern Song Dynasty, but there is no detailed research which can prove this presumption. It is also questionable whether Huan Tan Ji, Yue Yuan Qi, Qin Cao, and Tai Chu Li Fa are written by Huan Tan, as some unorthodox documents has indicated This paper solves these questions with historical records and other related materials.