「孝」是中國傳統社會最高的倫理道德。在儒家看來，孝道是人類存在的根本，教化發展之由來，道德成就之所生，因此，面對外來的佛教，須捨離人倫，剃髮出家修行，必定強烈攻擊其不孝或不講孝道思想。佛教不講求「孝」？亦或不主張孝道？如若不然，佛、儒二家的孝又有何相異之處？本文所關注的重點在於佛日契嵩擬儒《孝經》，以釋儒會通的主張撰寫《輔教編．孝論》一文，大力挖掘佛教無時無盡的孝道思想，使世人了解佛教的「孝」反而是「大孝」、「廣孝」，以闡明佛教和儒家一樣，亦極尊崇與重視「孝」。因論述需要，亦對契嵩生平，交友情形，〈孝論〉釋儒會通的背景予以闡述，俾能更明瞭契嵩的援儒入佛之思想基底，以利於對其儒佛一致的孝道思想作分析和解讀。

「Piety （Hsiao 孝）」 is the highest ethical morality conception at Chinese traditional society. In Confucian viewpoint, filial piety is foundation of human existence, origin of enlightening development by education and birth of morality achievement, and therefore, Confucianism faces imported Buddhism that has to vanish human nature then has a haircut to become a monk so as to cultivate,must violently criticize and attack Buddhism that has un-filial piety or does not speak filial piety thought. Doesn’t Buddhism speak piety （hsiao）, or doesn’t Buddhism advocate stressing filial piety? If not, what does has different between Buddhist piety （hsiao） and Confucian piety （hsiao）? This essay is to discuss that focuses on that Monk Fo-ri Ch'i-sung （佛日契嵩） drafts book on 《The Classic of Filial Piety （ Shoo King 孝經）》to compose《Fu-chiao-pien．Hsiao Lun （孝論）》based on Buddhist-Confucian Interaction Thought to excavate Buddhism timeless and endless filial piety thought with great exertion so as to make common people to understand 「piety （hsiao）」 of Buddhism is 「great piety （da hsiao 大孝）」、「wide piety （guang hsiao 廣孝）」, expound Buddhism is the same as Confucian that highly praises and respects 「piety （hsiao）」. Because of Interpretation demand, this essay expounds Ch'i-sung’s life story, friend-making situation as well background of 〈Hsiao Lun〉Buddhist-Confucian Interaction in order to understand even more the thought base of Ch'i-sung aids Confucianism then enter Buddhism in order to benefit filial piety thought of Buddhist-Confucian Unanimity and do analysis and understand.