Abstract:The name of the first version of Zuozhuan which put forward originally by Gu Jiegang refers to the initial written form of Zuozhuan.We can discover that the first version of Zuozhuan is not The Zuoshichunqiu but The Kongzishiji through detailed explanation on The Biography of Liu Xin in Hanshu and The Sequence of 12 Princes Chronology in Shiji,which constitutes the backbone of The Zuoshichunqiu and later various versions.Although the Zuozhuan often changed during the spread of more than 2000 years,its core content,which was The Kongzishiji,was basically unchanged.We can further understand the nature of Zuozhuan by figuring out the fact that the first version of Zuozhuan is The Kongzishiji or Kongchunqiu.