呼吸一法，在內丹工夫論當中，佔據十分關鍵的地位，不了解呼吸，即無法了解內丹工夫論的詳情。本論文之主旨，即在探討內丹呼吸說之源流、種類、內涵、次第、操作方法及相應徵驗，並旁及內丹與儒、釋二家呼吸說異同的比較。全文首先論述呼吸一法，在佛學、瑜伽、內丹及儒學工夫論當中，所佔據之重要地位。其次，則概略論述早期道教呼吸法的發展演變情形及其對內丹呼吸說的影響。第三節，主要剖析內丹論呼吸之不同種類、不同呼吸方法之特質及彼此間之關係。第四節，則是以內丹之煉精化炁工夫爲例，詳細解析丹家如何運用呼吸來行內丹之修煉。最後一節所探討的，是內丹呼吸修煉之整體過程、次第以及相應產生之各種效驗。

The methods of breath occupy a very important position in the practice theory of Taoist Inner Alchemy. We cannot understand the practice theory of Inner Alchemy without understanding the breath theory of Taoist Inner Alchemy. This article aims at probing the beginnings, history, kinds, methods and effect of breath theory of Inner Alchemy. Besides we attempt to compare the breath theory of Inner Alchemy with Confusianism and Buddhism. In the first Section we explore the importance of breath method in Buddhism, Yoga, Taoist Inner Alchemy and Confusianism. The second section explores the evolvement of early Daoist breath theories and their impact on the breath theory of Inner alchemy. The third section analyzes the different kinds and methods of breath of Inner Alchemy. The last section probes the process, grades and effect of breath practice of Inner Alchemy.