古代法是由习惯法到成文法的演变。而成文法又分为秘密时期和后来的法公开时期。在秘密法年代,执法者握有无上的权威。司法官仅凭自身对礼教道德的理解进行判案,有许多的任意性和不确定性。直至新兴阶级根据自己的需要将成文法颁布于天下,在其确立自身统治的同时,也开启了成文法时代的大门。本文力求从“信史”《左传》中挖掘一些史料,以期能窥见成文法启蒙时代的些许景象。 Ancient law is the evolution from customary law to statutory law. The statutory law is divided into the secret period and later the legal open period. In the era of the secret law, law enforcement holds the supreme authority. Judges judge cases based on their own understanding of the ethics of rites and has many arbitrariness and uncertainty. Until the emerging class promulgates the statute law according to its own needs, it also opens the door of the era of the statute law while establishing its own rule. This article seeks to excavate some historical materials from “Letter History ” “Zuo Zhuan ”, in order to be able to have a glimpse of a little scene of the Enlightenment era of the statute law.