The Sung Dynasty is the crucial period of time during which Kung-an Chan evolved into Hua-t’ou Chan. Yuan-wu K’o-ch’in played an important role during this period of time. Previously, a majority of scholarly studies emphasized the Kung-an of “Pi-yen” lu and K’o-ch’in’s commentary of these Kung-an, positioning him as one of the promoters of Wen-tzu Chan (the lettered Chan). Was K’o-ch’in’s praxis merely Wen-tzu Chan causing Chan’s decline? This study will analyze and explore “The Recorded Sayings of Chan Master Yūan-Wu Fo-Kuo”, revealing K’o-ch’in’s praxis, and discuss his place in the history of Chinese Chan. This thesis will use historical based induction to discuss K’o-ch’in’s biography and the edition of “recorded sayings”. It will provide analysis and comparison of the unique praxis found in his sermons and teachings for monks, nuns, and laypersons. In general, K’o-ch’in employed Lin-chi Chan praxis while coaching his disciples, especially Kung-an. In addition, this study finds the evidence of Hua-yen thought , pure land belief and use of the Lankavatara-Sutra as the teaching material in “recorded sayings”. Even though K’o-ch’in was regarded as a promoter of Wen-tzu Chan, this study will reveal another aspect of his Chan praxis. By instructing practitioners to investigate specific phrases of Kung-an in order to cut off their thoughts and discriminations to purify the mind, K’o-ch’in reveals that his instructions have the outline and spiritual mark of Hua-t’ou. Therefore, K’o-ch’in’s instructions on investigating Kung-an accumulated enough experience and energy to make Hua-t’ou popular in the Sung period. Following him, his outstanding disciple Ta-hui Tsung-kao simplified the practice method of Kung-an. Due mainly to their efforts, Hua-t’ou become a unique and innovative practice method in Chinese Buddhism.