清代宋常星的《道德經講義》代表了全真道龍門派的丹道詮釋角度，此書內容包含了全真龍門的丹道修煉功法，可以見出通過此一修煉，所展開的全真龍門的特有的道家哲學和身體觀。筆者於此文之中，以道家身體觀、功夫論（本體詮釋學的實踐詮釋學）、象徵詮釋學的研究角度，解說宋常星的《道德經講義》中的龍門丹道修煉方法與境界，並闡明《道德經講義》所說的「玄北之門」與全真龍門丹道起手處。

Song Jing-xing's Comment on Tao-te-king in Ching Dynasty is one of the most important dantaoist commentary on Tao-te-king. This paper tackles Song Jing-xing's Comment on Tao-te-king and its relationship with Dragon-Door's Dantao. This paper exposits the symbol hermeneutics of Song Jing-xing's Comment in order to illuminate the Taoist body of Dragon-Door's Dantao.