Pursuant to Article 9 of Negotiable Instruments Act, an agent who signs a negotiable instrument without expressly indicating that he signs on behalf of the principal shall be personally liable on the instrument. In addition, a person who signs his name to a negotiable instrument is liable thereon according to its tenor and where a negotiable instrument is signed by two or more persons together, they are jointly and severally liable thereon under Article 5 of Negotiable Instruments Act. Accordingly, any person as an undisclosed agent is supposed to be personally liable on the instrument. However, the Tai-Shang-Tzu No. 764 Judgment of Supreme Court in the Year of 41 held that undisclosed agency would be effective under certain circumstances, which makes it arguable whether a person other than a statutory agent as an undisclosed agent for a juridical person shall be jointly and severally liable with the juridical person on the instrument. For the purpose of the circulation and transaction security, negotiable instruments should be in accordance with the principles of literal construction and objective interpretation. In the light of most court decisions, it is essential for effective undisclosed agency to have apparent discriminability from the drawing of a negotiable instrument. The distance between seals/signatures on a negotiable instrument would be a lack of significant discriminability. Moreover, the authorized seal or signature on cash disbursement forms is not enough to fight against the holder of a negotiable instrument. Based on the analysis of the aforementioned purposes, principles and judgment precedents, this paper discusses the Jian-Shang-Tzu No. 108 Judgment of Hsinchu District Court in the Year of 104.