Abstract: “Small annotate” is a unique way of commenting on the law in traditional Chinese legal codes and existed in Tang, Song, Ming and Qing legal codes widely. It originated from Zhang Fei and Du Yu in the Jin Dynasty annotated Taishi Law, but at that time, the annotations of Zhang and Du were not published together with Taishi Law. The Yongming Law in the Nanqi Dynasty was the first time to publish the law and annotation together, but it was not officially promulgated. Liang Law inherited the compilation experience of Yongming Law, became the first officially promulgated legal code with a combination of law and annotation. The legislation of the Northern Dynasties was influenced by the Southern Dynasties, it can be annotated and interpreted legal code skillfully. Judging from the Tang Dynasty handwritten Tang Law which was unearthed in Dunhuang, the annotations of the legal code had appeared in the form of “small annotation”. So the statement that the small annotation was appended in Tang Law by people in the Song Dynasty is not correct.