In this paper, the author reports his discovery of the remnants of the first draft of Tong-jian Gang-mu (資治通鑑綱目) in Da-shi-ji (大事記) of Lu-zuqian (呂祖謙) and offers his analysis and estimations of the extent this discovery can have. There has been long and complicated controversies concerning the authenticity of fanli (凡例) of Tong-jian Gang-mu (資治通鑑綱目). Opinions prevailing the current scholars are negative with a minority that asserts the genuineness. Based upon his discovery, the author corroborates that the predetermined set of principles (凡例) of zhe current version of Gang-mu is likely to originate from the text which Zhu-xi wrote in 1184-1190.