This paper examines Dogen（道元）'s understanding of Hongzhizhengjue（宏智正觉）. Hongzhizhengjue was a person of the Caodong Sect of the Southern Song period. Dogen referred to Hongzhizheng]ue as``Old Buddha", and when rating the various Zuochanzheng (坐禅箴) in the history of the Zen sect, he felt that only Hongzhizhengjue's version was worthy of serious attention, and accordingly copied the wording and structure when he wrote a similarly titled volume for inclusion in his Shobogenzo. The reason that Dogen stressed meditation was not just because of Rujing（如净）'s influence. To a large degree it was also because of his understanding of Hongzhizhengjue's thought. Bccause of this, when examining Dbgen's thought we cannot ignore the existence of Hongzhizh-engjue. Therefore, when Ddgen utilized Hongzhizhengjue words he did not simply copy them verbatim. Sometimes he modifiedpart of the wording, creating his own expressions. Some scholars believe that Dogen did this because he was not satisfied with Hongzhizhengjue's ideas, and attempted to surpass them. This chapter provides a detailed analysis of this question, and suggests that when Dogen made use of Hongzhizhengjue's words, even if he changed the wording, there were also times when he did not, and that neither situation was absolute. Additionally, we also investigated Dogen's understanding of Hongzhizhengjue's special features and point out that Dogen was firmly grounded in his own stress on practice perfection when he cried out in admiration of Hongzhizhengjue's ideas. This was not simply a case of blind promotion and worship; he had his own independent ideas.