This paper examines the nature of Yiqing of Huatou Chan's teaching of Master Sheng Yen; trying to clarify the nature of Yiqing. Taking the traditional Abhidharma classification and definition of dharma, the paper examines the concept of what are the mental factors of Yiqing according to the concept of the Baifa mingmen lun of the Yogachara school. First, I will introduce the teaching of Huatou Chan and Yiqing of Master Sheng Yen. I have compiled a list of eight subsections to introduce the teaching, including 1 Understanding the Huatou Chan Meditation, 2 Preliminary steps in the practice of Huatou Chan Meditation and the way to practice, 3 Attitude and awareness in the practice of Huatou Chan, 4 The hierarchy of the method of Huatou Chan, 5 The role of Yiqing and Yiqing Groups in enlightenment, 6 The way of Yiqing initiation, 7 The kung fu levels of Huatou Chan, 8 The situation of enlightenment and how to do the work after enlightenment. Master Sheng Yen pointed out as follows: to create Yiqing with Huatou, to Yi(疑 )what is the origin of birth and death, to Yi what is the root of the trouble, to help oneself to discover what life and death are. When Yiqing Groups break down and shatter, the obsessions, worries, and self-centeredness are also shattered at the same time, this is the time to experience true freedom. Yiqing is not doubt or suspicion, but a feeling of puzzlement and a sense of questioning that arises when you ask yourself questions with the Huatou, or when you ask questions. " Big Yi and big enlightenment, small Yi and small enlightenment, no Yi and no enlightenment. " Yiqing can be described as a thought or imagination of a "question or problem situation" that the mind desperately wants to know but does not know, so it is a state of mind. " It is not necessarily that there is something to ask when you get into a Yiqing Groups situation, but rather that you feel you are surrounded by Yiqing Groups and have a boring feeling. " " When you really enter into Yiqing Groups, you will reach the level of seeing without seeing, hearing without hearing, and eating without knowing its taste. " After the author's exploration and analysis, In "citta-dharma(心法 )", " Yiqing " and " Yiqing Groups " do not correspond to the first five " vijñāna(識 )"; " Yiqing " corresponds to the " mano-vijñāna(第六意識 )" "manas(第七末那識 )" and "ālaya-vijñāna(第八阿賴耶識 )", while " Yiqing Groups " initially corresponds to the " Soly Dhyāna (定中獨頭意識 )" of" mano-vijñāna(第六意識 )", and correspond to the "manas(第七意識 )" "ālaya-vijñāna(第八 阿賴耶識 )". But, " Yiqing Groups "is chaning(參 )with the wisdom mind of Prajñā, and the ultimate goal of the " Yiqing Groups "is for the mind to cease to function, to be free of the "manas" "ālaya-vijñāna", to become mindless, and to see emptiness. Among the five "sarvatraga(遍行心所 )" in hundred dharma, the " Yiqing " is being tried an
