Abstract: This article explores the ideological unity of Lv‘s Spring and Autumn Annals《吕氏春秋》and also its ideological tenet and textual structure. The sequence of Eight Readings《八览》，Six Expositions《六论》，and Twelve Periods《十二纪》that are recorded in Historical Records《史记》reflects the order in which Lv’s team compiles the annals. The three parts function differently. Eight Readings gathers Pre-Qin Period‘s political and ideological resources and criticizes the advantages and disadvantages of Qin’s reign；Six Expositions further expounds on the basic principles of ideal politics；and Twelve Periods is the ultimate objective，which designs a framework of laws and rules for the new Qin dynasty and explains its ideological foundation. The compilation of Twelve Periods relies on the then popular taiyi-centered（ North Star）theory of qi universe and expresses a unity of ideologies. The theory mainly inherits and integrates the ideological achievements made during the middle and late period of the Warring States.

Key words: Lv’s Spring and Autumn Annals, Twelve Periods, Eight Readings, Six Expositions