Abstract: Addendum to Commentaries on Zhouyi with Collation Attached written by Japanese scholar Nagazawa Kikuya was based on transcript of Zhouyi Zhengyi written in Yuangui Tianzheng Period of Japan preserved in Jingjiatang Library, referring to other material, to compensate for the shortage and leakage made by Ruan Yuan. So the paper written by Nagazawa Kikuya is pretty valuable. But no one has do any specialized research on this paper so far. There is much special valuein Nagazawa Kikuya’s research. Firstly, the transcript of Zhouyi Zhengyi that Nagazawa Kikuya has used was copied by Japanese, and its value was revealed for the first time. Secondly, Nagazawa Kikuya made further collation on Zhouyi Zhengyi printed by Liu Chenggan. His achievement has surpassed well beyond that of Liu Chenggan. Ten line edition that Nagazawa Kikuya used is earlier than that of Ruan Yuanused, so it can annotate and correct Ruan yuan’s Commentaries on Zhouyi with Collation Attached.

Key words: Nagazawa Kikuya, Zhouyi Zhengyi, Collation, Addendum, Value