This paper examines the nineteen existent commentaries and forty editions of the Classic of Huang-Ting Nei-Jing, the earliest and most original work in Taoist Neidan. The first section deals with the basic procedure in the Neidan practice: the closure of the external senses and the commencement of the inward vision of the incorporeal body. The second section focuses on the diverse images of the incorporeal body in the various commentaries of the Classic of Huang-Ting Nei-Jing and to be used in the Neidan practice. The images are divided into two groups: one is the model of 'the incorporeal body resided by one spirit alone,' the other 'the incorporeal body resided by various spirits simultaneously.' The two models of the incorporeal body not only result from distinct interpretations of the Classic, but also establish two kinds of Taoist Neidan practice. The last section evaluates the two models and outlines how they had been respectively supported and discarded from the T'ang to the Qing.