「即心是佛，無心是道」這一句話可概括說明黃槧希運禪學之特色‧這些用語雖非出自黃槧希運的創見，但其詮釋之內容卻極為豐富，可使禪宗之，心-的觀念更為清楚、深入‧本文從本心與無心這兩個觀念，探討希運之心體觀‧首先說明即心定佛-這一說法的時代背景，了詳希運完全肯定比命題之用意‧其次探討即心定佛之涵義，包括如何認知本源清淨心，以及本心與見聞覺知的關係、心與性不異的看法‧冉討論無心之本體義與工夫義，以把握禪宗之無心的特貫‧最俊從本心、無心與真常唯心、如來藏思想以及空性思想之關係，說明希運之心體觀的意義與貢耿‧心是禪宗思想的重要內容，也定研究者不靳探討的問題‧本文希能從黃槧希運之心體觀得到較具體與完些的了解，以拓展研究的深度與廣度‧

Huangbo Xiyun (?-855) was a prominent Chan monk during the Tang dynasty. Although Xiyun did not actually say that "The Mind itself' is the Buddha" and that "The Non-intentional (無心) is the Dao,"these statements became catchphrases for his conception of Chan Buddhism. This paper will examine these two statements in order to disclose some aspects of Chan Buddhism during the Tang dynasty.Five topics will be discussed. The first concems the doctrinal background of the statement that "The Mind itself is the Buddha."The second topic is how one recognizes that the Mind is originally pure in seeing mental activities during meditation. The third topic is Xiyun's argument that the noumenally pure Mind is the substratum for ordinary cognition. The fourth topic is Xiyun's simile that the Mind in its ontic state is equivalent to nature in its primordial state. The last topic traces the two catchphrases for Xiyun's Chan thought back to the two Indian doctrines of Tath~gatagharba and Sfinyata. This paper suggests that these five topics can be the bases for more research into Chan Buddhism during the Tang dynasty.